diff --git a/.clang-tidy b/.clang-tidy
index 981246fbb172..3e39eb682ee8 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -24,6 +24,7 @@ WarningsAsErrors: 'abseil-duration-*,
                    modernize-make-unique,
                    modernize-return-braced-init-list,
                    modernize-use-equals-default,
+                   modernize-use-override,
                    modernize-use-using,
                    performance-faster-string-find,
                    performance-for-range-copy,
diff --git a/include/envoy/stats/stats.h b/include/envoy/stats/stats.h
index 21d19ffa21b4..f92715d9406b 100644
--- a/include/envoy/stats/stats.h
+++ b/include/envoy/stats/stats.h
@@ -22,7 +22,7 @@ struct Tag;
  */
 class Metric : public RefcountInterface {
 public:
-  virtual ~Metric() = default;
+  ~Metric() override = default;
   /**
    * Returns the full name of the Metric. This is intended for most uses, such
    * as streaming out the name to a stats sink or admin request, or comparing
diff --git a/source/common/access_log/access_log_manager_impl.h b/source/common/access_log/access_log_manager_impl.h
index df09d2ad7863..4a8dedcdf367 100644
--- a/source/common/access_log/access_log_manager_impl.h
+++ b/source/common/access_log/access_log_manager_impl.h
@@ -64,7 +64,7 @@ class AccessLogFileImpl : public AccessLogFile {
                     Thread::BasicLockable& lock, AccessLogFileStats& stats_,
                     std::chrono::milliseconds flush_interval_msec,
                     Thread::ThreadFactory& thread_factory);
-  ~AccessLogFileImpl();
+  ~AccessLogFileImpl() override;
 
   // AccessLog::AccessLogFile
   void write(absl::string_view data) override;
diff --git a/source/common/common/assert.cc b/source/common/common/assert.cc
index cb01008c121e..ab4b1b8776a4 100644
--- a/source/common/common/assert.cc
+++ b/source/common/common/assert.cc
@@ -10,7 +10,7 @@ class ActionRegistrationImpl : public ActionRegistration {
     debug_assertion_failure_record_action_ = action;
   }
 
-  ~ActionRegistrationImpl() {
+  ~ActionRegistrationImpl() override {
     ASSERT(debug_assertion_failure_record_action_ != nullptr);
     debug_assertion_failure_record_action_ = nullptr;
   }
diff --git a/source/common/config/grpc_mux_impl.h b/source/common/config/grpc_mux_impl.h
index 1181ef0dfec5..33ef94150822 100644
--- a/source/common/config/grpc_mux_impl.h
+++ b/source/common/config/grpc_mux_impl.h
@@ -29,7 +29,7 @@ class GrpcMuxImpl : public GrpcMux,
               Event::Dispatcher& dispatcher, const Protobuf::MethodDescriptor& service_method,
               Runtime::RandomGenerator& random, Stats::Scope& scope,
               const RateLimitSettings& rate_limit_settings);
-  ~GrpcMuxImpl();
+  ~GrpcMuxImpl() override;
 
   void start() override;
   GrpcMuxWatchPtr subscribe(const std::string& type_url, const std::set<std::string>& resources,
diff --git a/source/common/config/remote_data_fetcher.h b/source/common/config/remote_data_fetcher.h
index 687dfe8a7ef9..6455e44abf1b 100644
--- a/source/common/config/remote_data_fetcher.h
+++ b/source/common/config/remote_data_fetcher.h
@@ -47,7 +47,7 @@ class RemoteDataFetcher : public Logger::Loggable<Logger::Id::config>,
   RemoteDataFetcher(Upstream::ClusterManager& cm, const ::envoy::api::v2::core::HttpUri& uri,
                     const std::string& content_hash, RemoteDataFetcherCallback& callback);
 
-  virtual ~RemoteDataFetcher() override;
+  ~RemoteDataFetcher() override;
 
   // Http::AsyncClient::Callbacks
   void onSuccess(Http::MessagePtr&& response) override;
diff --git a/source/common/event/dispatcher_impl.h b/source/common/event/dispatcher_impl.h
index 3777762265b1..508e18e2a312 100644
--- a/source/common/event/dispatcher_impl.h
+++ b/source/common/event/dispatcher_impl.h
@@ -33,7 +33,7 @@ class DispatcherImpl : Logger::Loggable<Logger::Id::main>,
   DispatcherImpl(Api::Api& api, Event::TimeSystem& time_system);
   DispatcherImpl(Buffer::WatermarkFactoryPtr&& factory, Api::Api& api,
                  Event::TimeSystem& time_system);
-  ~DispatcherImpl();
+  ~DispatcherImpl() override;
 
   /**
    * @return event_base& the libevent base.
diff --git a/source/common/filesystem/posix/directory_iterator_impl.h b/source/common/filesystem/posix/directory_iterator_impl.h
index 513b5f98406d..889ffef1b5ac 100644
--- a/source/common/filesystem/posix/directory_iterator_impl.h
+++ b/source/common/filesystem/posix/directory_iterator_impl.h
@@ -15,7 +15,7 @@ class DirectoryIteratorImpl : public DirectoryIterator {
   DirectoryIteratorImpl()
       : directory_path_(""), dir_(nullptr), os_sys_calls_(Api::OsSysCallsSingleton::get()) {}
 
-  ~DirectoryIteratorImpl();
+  ~DirectoryIteratorImpl() override;
 
   DirectoryIteratorImpl& operator++() override;
 
diff --git a/source/common/grpc/google_async_client_impl.h b/source/common/grpc/google_async_client_impl.h
index b14456235b21..f2e9eb651b7e 100644
--- a/source/common/grpc/google_async_client_impl.h
+++ b/source/common/grpc/google_async_client_impl.h
@@ -66,7 +66,7 @@ class GoogleAsyncClientThreadLocal : public ThreadLocal::ThreadLocalObject,
                                      Logger::Loggable<Logger::Id::grpc> {
 public:
   GoogleAsyncClientThreadLocal(Api::Api& api);
-  ~GoogleAsyncClientThreadLocal();
+  ~GoogleAsyncClientThreadLocal() override;
 
   grpc::CompletionQueue& completionQueue() { return cq_; }
 
@@ -199,7 +199,7 @@ class GoogleAsyncStreamImpl : public RawAsyncStream,
   GoogleAsyncStreamImpl(GoogleAsyncClientImpl& parent, absl::string_view service_full_name,
                         absl::string_view method_name, RawAsyncStreamCallbacks& callbacks,
                         const absl::optional<std::chrono::milliseconds>& timeout);
-  ~GoogleAsyncStreamImpl();
+  ~GoogleAsyncStreamImpl() override;
 
   virtual void initialize(bool buffer_body_for_retry);
 
diff --git a/source/common/http/codec_client.h b/source/common/http/codec_client.h
index 4bf2487da76c..cc27050e8fbe 100644
--- a/source/common/http/codec_client.h
+++ b/source/common/http/codec_client.h
@@ -53,7 +53,7 @@ class CodecClient : Logger::Loggable<Logger::Id::client>,
    */
   enum class Type { HTTP1, HTTP2 };
 
-  ~CodecClient();
+  ~CodecClient() override;
 
   /**
    * Add a connection callback to the underlying network connection.
diff --git a/source/common/http/http1/codec_impl.h b/source/common/http/http1/codec_impl.h
index a9bf7111b73b..a15bdbe913ff 100644
--- a/source/common/http/http1/codec_impl.h
+++ b/source/common/http/http1/codec_impl.h
@@ -300,7 +300,7 @@ class ServerConnectionImpl : public ServerConnection, public ConnectionImpl {
                        Http1Settings settings, uint32_t max_request_headers_kb,
                        bool strict_header_validation);
 
-  virtual bool supports_http_10() override { return codec_settings_.accept_http_10_; }
+  bool supports_http_10() override { return codec_settings_.accept_http_10_; }
 
 private:
   /**
diff --git a/source/common/http/http2/codec_impl.h b/source/common/http/http2/codec_impl.h
index 0b8c8bd0c4be..c8df6ee4499d 100644
--- a/source/common/http/http2/codec_impl.h
+++ b/source/common/http/http2/codec_impl.h
@@ -80,7 +80,7 @@ class ConnectionImpl : public virtual Connection, protected Logger::Loggable<Log
         per_stream_buffer_limit_(http2_settings.initial_stream_window_size_), dispatching_(false),
         raised_goaway_(false), pending_deferred_reset_(false) {}
 
-  ~ConnectionImpl();
+  ~ConnectionImpl() override;
 
   // Http::Connection
   void dispatch(Buffer::Instance& data) override;
diff --git a/source/common/http/http2/conn_pool.h b/source/common/http/http2/conn_pool.h
index 774f654816ac..c551299fd396 100644
--- a/source/common/http/http2/conn_pool.h
+++ b/source/common/http/http2/conn_pool.h
@@ -27,7 +27,7 @@ class ConnPoolImpl : public ConnectionPool::Instance, public ConnPoolImplBase {
   ConnPoolImpl(Event::Dispatcher& dispatcher, Upstream::HostConstSharedPtr host,
                Upstream::ResourcePriority priority,
                const Network::ConnectionSocket::OptionsSharedPtr& options);
-  ~ConnPoolImpl();
+  ~ConnPoolImpl() override;
 
   // Http::ConnectionPool::Instance
   Http::Protocol protocol() const override { return Http::Protocol::Http2; }
@@ -44,7 +44,7 @@ class ConnPoolImpl : public ConnectionPool::Instance, public ConnPoolImplBase {
                         public Event::DeferredDeletable,
                         public Http::ConnectionCallbacks {
     ActiveClient(ConnPoolImpl& parent);
-    ~ActiveClient();
+    ~ActiveClient() override;
 
     void onConnectTimeout() { parent_.onConnectTimeout(*this); }
 
diff --git a/source/common/network/listen_socket_impl.h b/source/common/network/listen_socket_impl.h
index 5ff5a35267ab..1ef7d60d8b40 100644
--- a/source/common/network/listen_socket_impl.h
+++ b/source/common/network/listen_socket_impl.h
@@ -16,7 +16,7 @@ namespace Network {
 
 class SocketImpl : public virtual Socket {
 public:
-  ~SocketImpl() { close(); }
+  ~SocketImpl() override { close(); }
 
   // Network::Socket
   const Address::InstanceConstSharedPtr& localAddress() const override { return local_address_; }
diff --git a/source/common/router/rds_impl.h b/source/common/router/rds_impl.h
index ee311b63a163..1b627cab2711 100644
--- a/source/common/router/rds_impl.h
+++ b/source/common/router/rds_impl.h
@@ -57,7 +57,7 @@ class StaticRouteConfigProviderImpl : public RouteConfigProvider {
   StaticRouteConfigProviderImpl(const envoy::api::v2::RouteConfiguration& config,
                                 Server::Configuration::FactoryContext& factory_context,
                                 RouteConfigProviderManagerImpl& route_config_provider_manager);
-  ~StaticRouteConfigProviderImpl();
+  ~StaticRouteConfigProviderImpl() override;
 
   // Router::RouteConfigProvider
   Router::ConfigConstSharedPtr config() override { return config_; }
diff --git a/source/common/router/retry_state_impl.h b/source/common/router/retry_state_impl.h
index 7177a3f2909f..fdc7f0d79396 100644
--- a/source/common/router/retry_state_impl.h
+++ b/source/common/router/retry_state_impl.h
@@ -27,7 +27,7 @@ class RetryStateImpl : public RetryState {
                               const Upstream::ClusterInfo& cluster, Runtime::Loader& runtime,
                               Runtime::RandomGenerator& random, Event::Dispatcher& dispatcher,
                               Upstream::ResourcePriority priority);
-  ~RetryStateImpl();
+  ~RetryStateImpl() override;
 
   /**
    * Returns the RetryPolicy extracted from the x-envoy-retry-on header.
diff --git a/source/common/router/router.h b/source/common/router/router.h
index 2767db0a2921..65d6d9a9f824 100644
--- a/source/common/router/router.h
+++ b/source/common/router/router.h
@@ -234,7 +234,7 @@ class Filter : Logger::Loggable<Logger::Id::router>,
         downstream_end_stream_(false), do_shadowing_(false), is_retry_(false),
         attempting_internal_redirect_with_complete_stream_(false) {}
 
-  ~Filter();
+  ~Filter() override;
 
   // Http::StreamFilterBase
   void onDestroy() override;
@@ -357,7 +357,7 @@ class Filter : Logger::Loggable<Logger::Id::router>,
                            public Http::ConnectionPool::Callbacks,
                            public LinkedObject<UpstreamRequest> {
     UpstreamRequest(Filter& parent, Http::ConnectionPool::Instance& pool);
-    ~UpstreamRequest();
+    ~UpstreamRequest() override;
 
     void encodeHeaders(bool end_stream);
     void encodeData(Buffer::Instance& data, bool end_stream);
diff --git a/source/common/stats/histogram_impl.h b/source/common/stats/histogram_impl.h
index 926b3496d2b0..0177d9f3317e 100644
--- a/source/common/stats/histogram_impl.h
+++ b/source/common/stats/histogram_impl.h
@@ -72,7 +72,7 @@ class HistogramImpl : public HistogramImplHelper {
                 const std::vector<Tag>& tags)
       : HistogramImplHelper(name, tag_extracted_name, tags, parent.symbolTable()), parent_(parent) {
   }
-  ~HistogramImpl() {
+  ~HistogramImpl() override {
     // We must explicitly free the StatName here in order to supply the
     // SymbolTable reference. An RAII alternative would be to store a
     // reference to the SymbolTable in MetricImpl, which would cost 8 bytes
@@ -99,7 +99,7 @@ class NullHistogramImpl : public HistogramImplHelper {
 public:
   explicit NullHistogramImpl(SymbolTable& symbol_table)
       : HistogramImplHelper(symbol_table), symbol_table_(symbol_table) {}
-  ~NullHistogramImpl() { MetricImpl::clear(symbol_table_); }
+  ~NullHistogramImpl() override { MetricImpl::clear(symbol_table_); }
 
   bool used() const override { return false; }
   SymbolTable& symbolTable() override { return symbol_table_; }
diff --git a/source/common/stats/scope_prefixer.h b/source/common/stats/scope_prefixer.h
index d4c63df99d8b..f85cfc3ff098 100644
--- a/source/common/stats/scope_prefixer.h
+++ b/source/common/stats/scope_prefixer.h
@@ -40,7 +40,7 @@ class ScopePrefixer : public Scope {
   OptionalHistogram findHistogram(StatName name) const override;
 
   const SymbolTable& constSymbolTable() const override { return scope_.constSymbolTable(); }
-  virtual SymbolTable& symbolTable() override { return scope_.symbolTable(); }
+  SymbolTable& symbolTable() override { return scope_.symbolTable(); }
 
   NullGaugeImpl& nullGauge(const std::string& str) override { return scope_.nullGauge(str); }
 
diff --git a/source/common/tcp/conn_pool.h b/source/common/tcp/conn_pool.h
index ff28802476cf..217b79cfdfbb 100644
--- a/source/common/tcp/conn_pool.h
+++ b/source/common/tcp/conn_pool.h
@@ -25,7 +25,7 @@ class ConnPoolImpl : Logger::Loggable<Logger::Id::pool>, public ConnectionPool::
                const Network::ConnectionSocket::OptionsSharedPtr& options,
                Network::TransportSocketOptionsSharedPtr transport_socket_options);
 
-  ~ConnPoolImpl();
+  ~ConnPoolImpl() override;
 
   // ConnectionPool::Instance
   void addDrainedCallback(DrainedCb cb) override;
@@ -59,7 +59,7 @@ class ConnPoolImpl : Logger::Loggable<Logger::Id::pool>, public ConnectionPool::
 
   struct ConnectionDataImpl : public ConnectionPool::ConnectionData {
     ConnectionDataImpl(ConnectionWrapperSharedPtr wrapper) : wrapper_(std::move(wrapper)) {}
-    ~ConnectionDataImpl() { wrapper_->release(false); }
+    ~ConnectionDataImpl() override { wrapper_->release(false); }
 
     // ConnectionPool::ConnectionData
     Network::ClientConnection& connection() override { return wrapper_->connection(); }
@@ -80,7 +80,7 @@ class ConnPoolImpl : Logger::Loggable<Logger::Id::pool>, public ConnectionPool::
     ConnReadFilter(ActiveConn& parent) : parent_(parent) {}
 
     // Network::ReadFilter
-    Network::FilterStatus onData(Buffer::Instance& data, bool end_stream) {
+    Network::FilterStatus onData(Buffer::Instance& data, bool end_stream) override {
       parent_.onUpstreamData(data, end_stream);
       return Network::FilterStatus::StopIteration;
     }
@@ -92,7 +92,7 @@ class ConnPoolImpl : Logger::Loggable<Logger::Id::pool>, public ConnectionPool::
                       public Network::ConnectionCallbacks,
                       public Event::DeferredDeletable {
     ActiveConn(ConnPoolImpl& parent);
-    ~ActiveConn();
+    ~ActiveConn() override;
 
     void onConnectTimeout();
     void onUpstreamData(Buffer::Instance& data, bool end_stream);
@@ -122,7 +122,7 @@ class ConnPoolImpl : Logger::Loggable<Logger::Id::pool>, public ConnectionPool::
 
   struct PendingRequest : LinkedObject<PendingRequest>, public ConnectionPool::Cancellable {
     PendingRequest(ConnPoolImpl& parent, ConnectionPool::Callbacks& callbacks);
-    ~PendingRequest();
+    ~PendingRequest() override;
 
     // ConnectionPool::Cancellable
     void cancel(ConnectionPool::CancelPolicy cancel_policy) override {
diff --git a/source/common/tcp_proxy/tcp_proxy.h b/source/common/tcp_proxy/tcp_proxy.h
index 44cdd35aeacf..5a8534a56287 100644
--- a/source/common/tcp_proxy/tcp_proxy.h
+++ b/source/common/tcp_proxy/tcp_proxy.h
@@ -178,7 +178,7 @@ class Filter : public Network::ReadFilter,
 public:
   Filter(ConfigSharedPtr config, Upstream::ClusterManager& cluster_manager,
          TimeSource& time_source);
-  ~Filter();
+  ~Filter() override;
 
   // Network::ReadFilter
   Network::FilterStatus onData(Buffer::Instance& data, bool end_stream) override;
@@ -315,7 +315,7 @@ using DrainerPtr = std::unique_ptr<Drainer>;
 
 class UpstreamDrainManager : public ThreadLocal::ThreadLocalObject {
 public:
-  ~UpstreamDrainManager();
+  ~UpstreamDrainManager() override;
   void add(const Config::SharedConfigSharedPtr& config,
            Tcp::ConnectionPool::ConnectionDataPtr&& upstream_conn_data,
            const std::shared_ptr<Filter::UpstreamCallbacks>& callbacks,
diff --git a/source/common/thread_local/thread_local_impl.h b/source/common/thread_local/thread_local_impl.h
index 820cd1504a95..25e346809f5a 100644
--- a/source/common/thread_local/thread_local_impl.h
+++ b/source/common/thread_local/thread_local_impl.h
@@ -18,7 +18,7 @@ namespace ThreadLocal {
 class InstanceImpl : Logger::Loggable<Logger::Id::main>, public Instance {
 public:
   InstanceImpl() : main_thread_id_(std::this_thread::get_id()) {}
-  ~InstanceImpl();
+  ~InstanceImpl() override;
 
   // ThreadLocal::Instance
   SlotPtr allocateSlot() override;
@@ -30,7 +30,7 @@ class InstanceImpl : Logger::Loggable<Logger::Id::main>, public Instance {
 private:
   struct SlotImpl : public Slot {
     SlotImpl(InstanceImpl& parent, uint64_t index) : parent_(parent), index_(index) {}
-    ~SlotImpl() { parent_.removeSlot(*this); }
+    ~SlotImpl() override { parent_.removeSlot(*this); }
 
     // ThreadLocal::Slot
     ThreadLocalObjectSharedPtr get() override;
diff --git a/source/common/upstream/cluster_factory_impl.h b/source/common/upstream/cluster_factory_impl.h
index cb5128a53763..ae709eb094c2 100644
--- a/source/common/upstream/cluster_factory_impl.h
+++ b/source/common/upstream/cluster_factory_impl.h
@@ -169,7 +169,7 @@ template <class ConfigProto> class ConfigurableClusterFactoryBase : public Clust
   ConfigurableClusterFactoryBase(const std::string& name) : ClusterFactoryImplBase(name) {}
 
 private:
-  virtual std::pair<ClusterImplBaseSharedPtr, ThreadAwareLoadBalancerPtr>
+  std::pair<ClusterImplBaseSharedPtr, ThreadAwareLoadBalancerPtr>
   createClusterImpl(const envoy::api::v2::Cluster& cluster, ClusterFactoryContext& context,
                     Server::Configuration::TransportSocketFactoryContext& socket_factory_context,
                     Stats::ScopePtr&& stats_scope) override {
diff --git a/source/common/upstream/cluster_manager_impl.h b/source/common/upstream/cluster_manager_impl.h
index abe595033747..055cb9fd2cce 100644
--- a/source/common/upstream/cluster_manager_impl.h
+++ b/source/common/upstream/cluster_manager_impl.h
@@ -293,7 +293,7 @@ class ClusterManagerImpl : public ClusterManager, Logger::Loggable<Logger::Id::u
     struct ClusterEntry : public ThreadLocalCluster {
       ClusterEntry(ThreadLocalClusterManagerImpl& parent, ClusterInfoConstSharedPtr cluster,
                    const LoadBalancerFactorySharedPtr& lb_factory);
-      ~ClusterEntry();
+      ~ClusterEntry() override;
 
       Http::ConnectionPool::Instance* connPool(ResourcePriority priority, Http::Protocol protocol,
                                                LoadBalancerContext* context);
@@ -323,7 +323,7 @@ class ClusterManagerImpl : public ClusterManager, Logger::Loggable<Logger::Id::u
 
     ThreadLocalClusterManagerImpl(ClusterManagerImpl& parent, Event::Dispatcher& dispatcher,
                                   const absl::optional<std::string>& local_cluster_name);
-    ~ThreadLocalClusterManagerImpl();
+    ~ThreadLocalClusterManagerImpl() override;
     void drainConnPools(const HostVector& hosts);
     void drainConnPools(HostSharedPtr old_host, ConnPoolsContainer& container);
     void clearContainer(HostSharedPtr old_host, ConnPoolsContainer& container);
diff --git a/source/common/upstream/health_checker_base_impl.h b/source/common/upstream/health_checker_base_impl.h
index 39aa9a8687aa..5008cf9d3907 100644
--- a/source/common/upstream/health_checker_base_impl.h
+++ b/source/common/upstream/health_checker_base_impl.h
@@ -46,7 +46,7 @@ class HealthCheckerImplBase : public HealthChecker,
 protected:
   class ActiveHealthCheckSession : public Event::DeferredDeletable {
   public:
-    virtual ~ActiveHealthCheckSession();
+    ~ActiveHealthCheckSession() override;
     HealthTransition setUnhealthy(envoy::data::core::v2alpha::HealthCheckFailureType type);
     void onDeferredDeleteBase();
     void start() { onInitialInterval(); }
diff --git a/source/common/upstream/load_balancer_impl.h b/source/common/upstream/load_balancer_impl.h
index 79e3a1eca77d..518ea5071121 100644
--- a/source/common/upstream/load_balancer_impl.h
+++ b/source/common/upstream/load_balancer_impl.h
@@ -162,7 +162,7 @@ class ZoneAwareLoadBalancerBase : public LoadBalancerBase {
                             ClusterStats& stats, Runtime::Loader& runtime,
                             Runtime::RandomGenerator& random,
                             const envoy::api::v2::Cluster::CommonLbConfig& common_config);
-  ~ZoneAwareLoadBalancerBase();
+  ~ZoneAwareLoadBalancerBase() override;
 
   // When deciding which hosts to use on an LB decision, we need to know how to index into the
   // priority_set. This priority_set cursor is used by ZoneAwareLoadBalancerBase subclasses, e.g.
diff --git a/source/common/upstream/outlier_detection_impl.h b/source/common/upstream/outlier_detection_impl.h
index 3a03a7556c00..2b703c2adba4 100644
--- a/source/common/upstream/outlier_detection_impl.h
+++ b/source/common/upstream/outlier_detection_impl.h
@@ -290,7 +290,7 @@ class DetectorImpl : public Detector, public std::enable_shared_from_this<Detect
   create(const Cluster& cluster, const envoy::api::v2::cluster::OutlierDetection& config,
          Event::Dispatcher& dispatcher, Runtime::Loader& runtime, TimeSource& time_source,
          EventLoggerSharedPtr event_logger);
-  ~DetectorImpl();
+  ~DetectorImpl() override;
 
   void onConsecutive5xx(HostSharedPtr host);
   void onConsecutiveGatewayFailure(HostSharedPtr host);
diff --git a/source/common/upstream/resource_manager_impl.h b/source/common/upstream/resource_manager_impl.h
index 48ae3bb85969..8ba81886f56f 100644
--- a/source/common/upstream/resource_manager_impl.h
+++ b/source/common/upstream/resource_manager_impl.h
@@ -55,7 +55,7 @@ class ResourceManagerImpl : public ResourceManager {
           remaining_(remaining) {
       remaining_.set(max);
     }
-    ~ResourceImpl() { ASSERT(current_ == 0); }
+    ~ResourceImpl() override { ASSERT(current_ == 0); }
 
     // Upstream::Resource
     bool canCreate() override { return current_ < max(); }
diff --git a/source/common/upstream/upstream_impl.h b/source/common/upstream/upstream_impl.h
index 5d07e9a1673f..70a7ab3c3617 100644
--- a/source/common/upstream/upstream_impl.h
+++ b/source/common/upstream/upstream_impl.h
@@ -105,7 +105,7 @@ class HostDescriptionImpl : virtual public HostDescription {
     absl::ReaderMutexLock lock(&metadata_mutex_);
     return metadata_;
   }
-  virtual void metadata(const envoy::api::v2::core::Metadata& new_metadata) override {
+  void metadata(const envoy::api::v2::core::Metadata& new_metadata) override {
     absl::WriterMutexLock lock(&metadata_mutex_);
     metadata_ = std::make_shared<envoy::api::v2::core::Metadata>(new_metadata);
   }
@@ -483,13 +483,12 @@ class PrioritySetImpl : public PrioritySet {
       ASSERT(!parent_.batch_update_);
       parent_.batch_update_ = true;
     }
-    ~BatchUpdateScope() { parent_.batch_update_ = false; }
+    ~BatchUpdateScope() override { parent_.batch_update_ = false; }
 
-    virtual void updateHosts(uint32_t priority,
-                             PrioritySet::UpdateHostsParams&& update_hosts_params,
-                             LocalityWeightsConstSharedPtr locality_weights,
-                             const HostVector& hosts_added, const HostVector& hosts_removed,
-                             absl::optional<uint32_t> overprovisioning_factor) override;
+    void updateHosts(uint32_t priority, PrioritySet::UpdateHostsParams&& update_hosts_params,
+                     LocalityWeightsConstSharedPtr locality_weights, const HostVector& hosts_added,
+                     const HostVector& hosts_removed,
+                     absl::optional<uint32_t> overprovisioning_factor) override;
 
     std::unordered_set<HostSharedPtr> all_hosts_added_;
     std::unordered_set<HostSharedPtr> all_hosts_removed_;
diff --git a/source/extensions/common/dynamic_forward_proxy/dns_cache_impl.h b/source/extensions/common/dynamic_forward_proxy/dns_cache_impl.h
index 440617b61c70..af3b81704b38 100644
--- a/source/extensions/common/dynamic_forward_proxy/dns_cache_impl.h
+++ b/source/extensions/common/dynamic_forward_proxy/dns_cache_impl.h
@@ -39,7 +39,7 @@ class DnsCacheImpl : public DnsCache, Logger::Loggable<Logger::Id::forward_proxy
   DnsCacheImpl(Event::Dispatcher& main_thread_dispatcher, ThreadLocal::SlotAllocator& tls,
                Stats::Scope& root_scope,
                const envoy::config::common::dynamic_forward_proxy::v2alpha::DnsCacheConfig& config);
-  ~DnsCacheImpl();
+  ~DnsCacheImpl() override;
 
   // DnsCache
   LoadDnsCacheEntryResult loadDnsCacheEntry(absl::string_view host, uint16_t default_port,
@@ -63,7 +63,7 @@ class DnsCacheImpl : public DnsCache, Logger::Loggable<Logger::Id::forward_proxy
 
   // Per-thread DNS cache info including the currently known hosts as well as any pending callbacks.
   struct ThreadLocalHostInfo : public ThreadLocal::ThreadLocalObject {
-    ~ThreadLocalHostInfo();
+    ~ThreadLocalHostInfo() override;
     void updateHostMap(const TlsHostMapSharedPtr& new_host_map);
 
     TlsHostMapSharedPtr host_map_;
diff --git a/source/extensions/common/dynamic_forward_proxy/dns_cache_manager_impl.h b/source/extensions/common/dynamic_forward_proxy/dns_cache_manager_impl.h
index 7b195f4c0883..cdd4249a4c93 100644
--- a/source/extensions/common/dynamic_forward_proxy/dns_cache_manager_impl.h
+++ b/source/extensions/common/dynamic_forward_proxy/dns_cache_manager_impl.h
@@ -16,8 +16,8 @@ class DnsCacheManagerImpl : public DnsCacheManager, public Singleton::Instance {
       : main_thread_dispatcher_(main_thread_dispatcher), tls_(tls), root_scope_(root_scope) {}
 
   // DnsCacheManager
-  DnsCacheSharedPtr
-  getCache(const envoy::config::common::dynamic_forward_proxy::v2alpha::DnsCacheConfig& config);
+  DnsCacheSharedPtr getCache(
+      const envoy::config::common::dynamic_forward_proxy::v2alpha::DnsCacheConfig& config) override;
 
 private:
   struct ActiveCache {
diff --git a/source/extensions/filters/common/ext_authz/ext_authz_grpc_impl.h b/source/extensions/filters/common/ext_authz/ext_authz_grpc_impl.h
index 6fa44003f50e..df06350ebf5d 100644
--- a/source/extensions/filters/common/ext_authz/ext_authz_grpc_impl.h
+++ b/source/extensions/filters/common/ext_authz/ext_authz_grpc_impl.h
@@ -50,7 +50,7 @@ class GrpcClientImpl : public Client, public ExtAuthzAsyncCallbacks {
   // TODO(gsagula): remove `use_alpha` param when V2Alpha gets deprecated.
   GrpcClientImpl(Grpc::RawAsyncClientPtr&& async_client,
                  const absl::optional<std::chrono::milliseconds>& timeout, bool use_alpha);
-  ~GrpcClientImpl();
+  ~GrpcClientImpl() override;
 
   // ExtAuthz::Client
   void cancel() override;
diff --git a/source/extensions/filters/common/ext_authz/ext_authz_http_impl.h b/source/extensions/filters/common/ext_authz/ext_authz_http_impl.h
index 376ccdc64c70..a26d5e4532f4 100644
--- a/source/extensions/filters/common/ext_authz/ext_authz_http_impl.h
+++ b/source/extensions/filters/common/ext_authz/ext_authz_http_impl.h
@@ -129,7 +129,7 @@ class RawHttpClientImpl : public Client,
                           Logger::Loggable<Logger::Id::config> {
 public:
   explicit RawHttpClientImpl(Upstream::ClusterManager& cm, ClientConfigSharedPtr config);
-  ~RawHttpClientImpl();
+  ~RawHttpClientImpl() override;
 
   // ExtAuthz::Client
   void cancel() override;
diff --git a/source/extensions/filters/common/original_src/original_src_socket_option.h b/source/extensions/filters/common/original_src/original_src_socket_option.h
index e030456c2089..3e428bf9b329 100644
--- a/source/extensions/filters/common/original_src/original_src_socket_option.h
+++ b/source/extensions/filters/common/original_src/original_src_socket_option.h
@@ -18,7 +18,7 @@ class OriginalSrcSocketOption : public Network::Socket::Option {
    * Constructs a socket option which will set the socket to use source @c src_address
    */
   OriginalSrcSocketOption(Network::Address::InstanceConstSharedPtr src_address);
-  ~OriginalSrcSocketOption() = default;
+  ~OriginalSrcSocketOption() override = default;
 
   /**
    * Updates the source address of the socket to match `src_address_`.
diff --git a/source/extensions/filters/common/ratelimit/ratelimit_impl.h b/source/extensions/filters/common/ratelimit/ratelimit_impl.h
index 11ca4c4396b0..fcd4cb520b1d 100644
--- a/source/extensions/filters/common/ratelimit/ratelimit_impl.h
+++ b/source/extensions/filters/common/ratelimit/ratelimit_impl.h
@@ -47,7 +47,7 @@ class GrpcClientImpl : public Client,
 public:
   GrpcClientImpl(Grpc::RawAsyncClientPtr&& async_client,
                  const absl::optional<std::chrono::milliseconds>& timeout);
-  ~GrpcClientImpl();
+  ~GrpcClientImpl() override;
 
   static void createRequest(envoy::service::ratelimit::v2::RateLimitRequest& request,
                             const std::string& domain,
diff --git a/source/extensions/filters/http/common/aws/credentials_provider_impl.h b/source/extensions/filters/http/common/aws/credentials_provider_impl.h
index 31e4d25d5d87..5f9b3816cfe0 100644
--- a/source/extensions/filters/http/common/aws/credentials_provider_impl.h
+++ b/source/extensions/filters/http/common/aws/credentials_provider_impl.h
@@ -98,7 +98,7 @@ class TaskRoleCredentialsProvider : public MetadataCredentialsProviderBase {
 class CredentialsProviderChain : public CredentialsProvider,
                                  public Logger::Loggable<Logger::Id::aws> {
 public:
-  virtual ~CredentialsProviderChain() = default;
+  ~CredentialsProviderChain() override = default;
 
   void add(const CredentialsProviderSharedPtr& credentials_provider) {
     providers_.emplace_back(credentials_provider);
diff --git a/source/extensions/filters/http/common/jwks_fetcher.cc b/source/extensions/filters/http/common/jwks_fetcher.cc
index d5c7a6c26d90..0eba021cf41e 100644
--- a/source/extensions/filters/http/common/jwks_fetcher.cc
+++ b/source/extensions/filters/http/common/jwks_fetcher.cc
@@ -18,9 +18,9 @@ class JwksFetcherImpl : public JwksFetcher,
 public:
   JwksFetcherImpl(Upstream::ClusterManager& cm) : cm_(cm) { ENVOY_LOG(trace, "{}", __func__); }
 
-  ~JwksFetcherImpl() { cancel(); }
+  ~JwksFetcherImpl() override { cancel(); }
 
-  void cancel() {
+  void cancel() override {
     if (request_ && !complete_) {
       request_->cancel();
       ENVOY_LOG(debug, "fetch pubkey [uri = {}]: canceled", uri_->uri());
@@ -28,7 +28,8 @@ class JwksFetcherImpl : public JwksFetcher,
     reset();
   }
 
-  void fetch(const ::envoy::api::v2::core::HttpUri& uri, JwksFetcher::JwksReceiver& receiver) {
+  void fetch(const ::envoy::api::v2::core::HttpUri& uri,
+             JwksFetcher::JwksReceiver& receiver) override {
     ENVOY_LOG(trace, "{}", __func__);
     ASSERT(!receiver_);
     complete_ = false;
@@ -44,7 +45,7 @@ class JwksFetcherImpl : public JwksFetcher,
   }
 
   // HTTP async receive methods
-  void onSuccess(Http::MessagePtr&& response) {
+  void onSuccess(Http::MessagePtr&& response) override {
     ENVOY_LOG(trace, "{}", __func__);
     complete_ = true;
     const uint64_t status_code = Http::Utility::getResponseStatus(response->headers());
@@ -74,7 +75,7 @@ class JwksFetcherImpl : public JwksFetcher,
     reset();
   }
 
-  void onFailure(Http::AsyncClient::FailureReason reason) {
+  void onFailure(Http::AsyncClient::FailureReason reason) override {
     ENVOY_LOG(debug, "{}: fetch pubkey [uri = {}]: network error {}", __func__, uri_->uri(),
               enumToInt(reason));
     complete_ = true;
diff --git a/source/extensions/filters/http/fault/fault_filter.h b/source/extensions/filters/http/fault/fault_filter.h
index b350ce61ce64..2a592c98a0f7 100644
--- a/source/extensions/filters/http/fault/fault_filter.h
+++ b/source/extensions/filters/http/fault/fault_filter.h
@@ -168,7 +168,7 @@ class StreamRateLimiter : Logger::Loggable<Logger::Id::filter> {
 class FaultFilter : public Http::StreamFilter, Logger::Loggable<Logger::Id::filter> {
 public:
   FaultFilter(FaultFilterConfigSharedPtr config);
-  ~FaultFilter();
+  ~FaultFilter() override;
 
   // Http::StreamFilterBase
   void onDestroy() override;
diff --git a/source/extensions/filters/http/grpc_json_transcoder/transcoder_input_stream_impl.h b/source/extensions/filters/http/grpc_json_transcoder/transcoder_input_stream_impl.h
index 7c4dfa4dc3f9..f5b4159be0d1 100644
--- a/source/extensions/filters/http/grpc_json_transcoder/transcoder_input_stream_impl.h
+++ b/source/extensions/filters/http/grpc_json_transcoder/transcoder_input_stream_impl.h
@@ -13,8 +13,8 @@ class TranscoderInputStreamImpl : public Buffer::ZeroCopyInputStreamImpl,
                                   public google::grpc::transcoding::TranscoderInputStream {
 public:
   // TranscoderInputStream
-  virtual int64_t BytesAvailable() const override;
-  virtual bool Finished() const override;
+  int64_t BytesAvailable() const override;
+  bool Finished() const override;
 };
 
 } // namespace GrpcJsonTranscoder
diff --git a/source/extensions/filters/http/header_to_metadata/header_to_metadata_filter.h b/source/extensions/filters/http/header_to_metadata/header_to_metadata_filter.h
index 188124e9d16f..e10da6e3eba9 100644
--- a/source/extensions/filters/http/header_to_metadata/header_to_metadata_filter.h
+++ b/source/extensions/filters/http/header_to_metadata/header_to_metadata_filter.h
@@ -66,7 +66,7 @@ class HeaderToMetadataFilter : public Http::StreamFilter,
                                public Logger::Loggable<Logger::Id::filter> {
 public:
   HeaderToMetadataFilter(const ConfigSharedPtr config);
-  ~HeaderToMetadataFilter();
+  ~HeaderToMetadataFilter() override;
 
   // Http::StreamFilterBase
   void onDestroy() override {}
diff --git a/source/extensions/filters/http/ip_tagging/ip_tagging_filter.h b/source/extensions/filters/http/ip_tagging/ip_tagging_filter.h
index 14a35a9a914b..3eaa7f22c841 100644
--- a/source/extensions/filters/http/ip_tagging/ip_tagging_filter.h
+++ b/source/extensions/filters/http/ip_tagging/ip_tagging_filter.h
@@ -107,7 +107,7 @@ using IpTaggingFilterConfigSharedPtr = std::shared_ptr<IpTaggingFilterConfig>;
 class IpTaggingFilter : public Http::StreamDecoderFilter {
 public:
   IpTaggingFilter(IpTaggingFilterConfigSharedPtr config);
-  ~IpTaggingFilter();
+  ~IpTaggingFilter() override;
 
   // Http::StreamFilterBase
   void onDestroy() override;
diff --git a/source/extensions/filters/network/common/redis/client_impl.h b/source/extensions/filters/network/common/redis/client_impl.h
index d88fc4c93e23..ffeb0ee458d8 100644
--- a/source/extensions/filters/network/common/redis/client_impl.h
+++ b/source/extensions/filters/network/common/redis/client_impl.h
@@ -65,7 +65,7 @@ class ClientImpl : public Client, public DecoderCallbacks, public Network::Conne
                           EncoderPtr&& encoder, DecoderFactory& decoder_factory,
                           const Config& config);
 
-  ~ClientImpl();
+  ~ClientImpl() override;
 
   // Client
   void addConnectionCallbacks(Network::ConnectionCallbacks& callbacks) override {
@@ -93,7 +93,7 @@ class ClientImpl : public Client, public DecoderCallbacks, public Network::Conne
 
   struct PendingRequest : public PoolRequest {
     PendingRequest(ClientImpl& parent, PoolCallbacks& callbacks);
-    ~PendingRequest();
+    ~PendingRequest() override;
 
     // PoolRequest
     void cancel() override;
diff --git a/source/extensions/filters/network/dubbo_proxy/decoder.h b/source/extensions/filters/network/dubbo_proxy/decoder.h
index 627dc314428b..2723633c79a6 100644
--- a/source/extensions/filters/network/dubbo_proxy/decoder.h
+++ b/source/extensions/filters/network/dubbo_proxy/decoder.h
@@ -128,7 +128,7 @@ class DecoderBase : public DecoderStateMachine::Delegate,
                     public Logger::Loggable<Logger::Id::dubbo> {
 public:
   DecoderBase(Protocol& protocol);
-  virtual ~DecoderBase();
+  ~DecoderBase() override;
 
   /**
    * Drains data from the given buffer
diff --git a/source/extensions/filters/network/dubbo_proxy/dubbo_hessian2_serializer_impl.h b/source/extensions/filters/network/dubbo_proxy/dubbo_hessian2_serializer_impl.h
index eeffb0c1044e..5af5e5d59622 100644
--- a/source/extensions/filters/network/dubbo_proxy/dubbo_hessian2_serializer_impl.h
+++ b/source/extensions/filters/network/dubbo_proxy/dubbo_hessian2_serializer_impl.h
@@ -8,20 +8,20 @@ namespace NetworkFilters {
 namespace DubboProxy {
 class DubboHessian2SerializerImpl : public Serializer {
 public:
-  ~DubboHessian2SerializerImpl() = default;
-  virtual const std::string& name() const override {
+  ~DubboHessian2SerializerImpl() override = default;
+  const std::string& name() const override {
     return ProtocolSerializerNames::get().fromType(ProtocolType::Dubbo, type());
   }
-  virtual SerializationType type() const override { return SerializationType::Hessian2; }
+  SerializationType type() const override { return SerializationType::Hessian2; }
 
-  virtual std::pair<RpcInvocationSharedPtr, bool>
+  std::pair<RpcInvocationSharedPtr, bool>
   deserializeRpcInvocation(Buffer::Instance& buffer, ContextSharedPtr context) override;
 
-  virtual std::pair<RpcResultSharedPtr, bool>
-  deserializeRpcResult(Buffer::Instance& buffer, ContextSharedPtr context) override;
+  std::pair<RpcResultSharedPtr, bool> deserializeRpcResult(Buffer::Instance& buffer,
+                                                           ContextSharedPtr context) override;
 
-  virtual size_t serializeRpcResult(Buffer::Instance& output_buffer, const std::string& content,
-                                    RpcResponseType type) override;
+  size_t serializeRpcResult(Buffer::Instance& output_buffer, const std::string& content,
+                            RpcResponseType type) override;
 };
 
 } // namespace DubboProxy
diff --git a/source/extensions/filters/network/dubbo_proxy/filters/filter.h b/source/extensions/filters/network/dubbo_proxy/filters/filter.h
index 5b4a5e5625c3..7ff4cbf5a030 100644
--- a/source/extensions/filters/network/dubbo_proxy/filters/filter.h
+++ b/source/extensions/filters/network/dubbo_proxy/filters/filter.h
@@ -115,7 +115,7 @@ class FilterCallbacksBase {
  */
 class DecoderFilterCallbacks : public virtual FilterCallbacksBase {
 public:
-  virtual ~DecoderFilterCallbacks() = default;
+  ~DecoderFilterCallbacks() override = default;
 
   /**
    * Continue iterating through the filter chain with buffered data. This routine can only be
@@ -158,7 +158,7 @@ class DecoderFilterCallbacks : public virtual FilterCallbacksBase {
  */
 class EncoderFilterCallbacks : public virtual FilterCallbacksBase {
 public:
-  virtual ~EncoderFilterCallbacks() = default;
+  ~EncoderFilterCallbacks() override = default;
 
   /**
    * Continue iterating through the filter chain with buffered data. This routine can only be
@@ -194,7 +194,7 @@ class FilterBase {
  */
 class DecoderFilter : public StreamDecoder, public FilterBase {
 public:
-  virtual ~DecoderFilter() = default;
+  ~DecoderFilter() override = default;
 
   /**
    * Called by the connection manager once to initialize the filter decoder callbacks that the
@@ -210,7 +210,7 @@ using DecoderFilterSharedPtr = std::shared_ptr<DecoderFilter>;
  */
 class EncoderFilter : public StreamEncoder, public FilterBase {
 public:
-  virtual ~EncoderFilter() = default;
+  ~EncoderFilter() override = default;
 
   /**
    * Called by the connection manager once to initialize the filter encoder callbacks that the
diff --git a/source/extensions/filters/network/dubbo_proxy/router/route_matcher.h b/source/extensions/filters/network/dubbo_proxy/router/route_matcher.h
index 551d658f6ba0..caa8b9ca3112 100644
--- a/source/extensions/filters/network/dubbo_proxy/router/route_matcher.h
+++ b/source/extensions/filters/network/dubbo_proxy/router/route_matcher.h
@@ -30,7 +30,7 @@ class RouteEntryImplBase : public RouteEntry,
                            public Logger::Loggable<Logger::Id::dubbo> {
 public:
   RouteEntryImplBase(const envoy::config::filter::network::dubbo_proxy::v2alpha1::Route& route);
-  virtual ~RouteEntryImplBase() = default;
+  ~RouteEntryImplBase() override = default;
 
   // Router::RouteEntry
   const std::string& clusterName() const override;
diff --git a/source/extensions/filters/network/dubbo_proxy/router/router_impl.h b/source/extensions/filters/network/dubbo_proxy/router/router_impl.h
index c4840015a5b5..9fc078a5aa4b 100644
--- a/source/extensions/filters/network/dubbo_proxy/router/router_impl.h
+++ b/source/extensions/filters/network/dubbo_proxy/router/router_impl.h
@@ -47,7 +47,7 @@ class Router : public Tcp::ConnectionPool::UpstreamCallbacks,
     UpstreamRequest(Router& parent, Tcp::ConnectionPool::Instance& pool,
                     MessageMetadataSharedPtr& metadata, SerializationType serialization_type,
                     ProtocolType protocol_type);
-    ~UpstreamRequest();
+    ~UpstreamRequest() override;
 
     FilterStatus start();
     void resetStream();
diff --git a/source/extensions/filters/network/ext_authz/ext_authz.h b/source/extensions/filters/network/ext_authz/ext_authz.h
index 276509c5d8e0..a0a963750be1 100644
--- a/source/extensions/filters/network/ext_authz/ext_authz.h
+++ b/source/extensions/filters/network/ext_authz/ext_authz.h
@@ -73,7 +73,7 @@ class Filter : public Network::ReadFilter,
 public:
   Filter(ConfigSharedPtr config, Filters::Common::ExtAuthz::ClientPtr&& client)
       : config_(config), client_(std::move(client)) {}
-  ~Filter() = default;
+  ~Filter() override = default;
 
   // Network::ReadFilter
   Network::FilterStatus onData(Buffer::Instance& data, bool end_stream) override;
diff --git a/source/extensions/filters/network/kafka/codec.h b/source/extensions/filters/network/kafka/codec.h
index 6dfe638d31d0..54e5709981be 100644
--- a/source/extensions/filters/network/kafka/codec.h
+++ b/source/extensions/filters/network/kafka/codec.h
@@ -48,7 +48,7 @@ template <typename MessageType, typename ParseFailureType> class MessageCallback
 template <typename ParserType, typename CallbackType>
 class AbstractMessageDecoder : public MessageDecoder {
 public:
-  virtual ~AbstractMessageDecoder() = default;
+  ~AbstractMessageDecoder() override = default;
 
   /**
    * Creates a decoder that will invoke given callbacks when a message has been parsed.
diff --git a/source/extensions/filters/network/mongo_proxy/proxy.h b/source/extensions/filters/network/mongo_proxy/proxy.h
index 35cdc29c17d1..f81ef86017ef 100644
--- a/source/extensions/filters/network/mongo_proxy/proxy.h
+++ b/source/extensions/filters/network/mongo_proxy/proxy.h
@@ -111,7 +111,7 @@ class ProxyFilter : public Network::Filter,
               const Filters::Common::Fault::FaultDelayConfigSharedPtr& fault_config,
               const Network::DrainDecision& drain_decision, TimeSource& time_system,
               bool emit_dynamic_metadata);
-  ~ProxyFilter();
+  ~ProxyFilter() override;
 
   virtual DecoderPtr createDecoder(DecoderCallbacks& callbacks) PURE;
 
diff --git a/source/extensions/filters/network/rbac/rbac_filter.h b/source/extensions/filters/network/rbac/rbac_filter.h
index 3fffefd23e93..b548424c63de 100644
--- a/source/extensions/filters/network/rbac/rbac_filter.h
+++ b/source/extensions/filters/network/rbac/rbac_filter.h
@@ -55,7 +55,7 @@ class RoleBasedAccessControlFilter : public Network::ReadFilter,
 public:
   RoleBasedAccessControlFilter(RoleBasedAccessControlFilterConfigSharedPtr config)
       : config_(config) {}
-  ~RoleBasedAccessControlFilter() = default;
+  ~RoleBasedAccessControlFilter() override = default;
 
   // Network::ReadFilter
   Network::FilterStatus onData(Buffer::Instance& data, bool end_stream) override;
diff --git a/source/extensions/filters/network/redis_proxy/command_splitter_impl.h b/source/extensions/filters/network/redis_proxy/command_splitter_impl.h
index e530fe8d3fdf..f4ee4c6f79d4 100644
--- a/source/extensions/filters/network/redis_proxy/command_splitter_impl.h
+++ b/source/extensions/filters/network/redis_proxy/command_splitter_impl.h
@@ -100,7 +100,7 @@ class SplitRequestBase : public SplitRequest {
  */
 class SingleServerRequest : public SplitRequestBase, public Common::Redis::Client::PoolCallbacks {
 public:
-  ~SingleServerRequest();
+  ~SingleServerRequest() override;
 
   // Common::Redis::Client::PoolCallbacks
   void onResponse(Common::Redis::RespValuePtr&& response) override;
@@ -158,7 +158,7 @@ class EvalRequest : public SingleServerRequest {
  */
 class FragmentedRequest : public SplitRequestBase {
 public:
-  ~FragmentedRequest();
+  ~FragmentedRequest() override;
 
   // RedisProxy::CommandSplitter::SplitRequest
   void cancel() override;
@@ -277,7 +277,7 @@ class CommandHandlerFactory : public CommandHandler, CommandHandlerBase {
   CommandHandlerFactory(Router& router) : CommandHandlerBase(router) {}
   SplitRequestPtr startRequest(Common::Redis::RespValuePtr&& request, SplitCallbacks& callbacks,
                                CommandStats& command_stats, TimeSource& time_source,
-                               bool latency_in_micros) {
+                               bool latency_in_micros) override {
     return RequestClass::create(router_, std::move(request), callbacks, command_stats, time_source,
                                 latency_in_micros);
   }
diff --git a/source/extensions/filters/network/redis_proxy/conn_pool_impl.h b/source/extensions/filters/network/redis_proxy/conn_pool_impl.h
index ff5b52ed5067..91ea51f3e752 100644
--- a/source/extensions/filters/network/redis_proxy/conn_pool_impl.h
+++ b/source/extensions/filters/network/redis_proxy/conn_pool_impl.h
@@ -84,7 +84,7 @@ class InstanceImpl : public Instance {
   struct ThreadLocalPool : public ThreadLocal::ThreadLocalObject,
                            public Upstream::ClusterUpdateCallbacks {
     ThreadLocalPool(InstanceImpl& parent, Event::Dispatcher& dispatcher, std::string cluster_name);
-    ~ThreadLocalPool();
+    ~ThreadLocalPool() override;
     ThreadLocalActiveClientPtr& threadLocalActiveClient(Upstream::HostConstSharedPtr host);
     Common::Redis::Client::PoolRequest*
     makeRequest(const std::string& key, const Common::Redis::RespValue& request,
diff --git a/source/extensions/filters/network/redis_proxy/proxy_filter.h b/source/extensions/filters/network/redis_proxy/proxy_filter.h
index d916a97f6fad..aefa3b9a7efa 100644
--- a/source/extensions/filters/network/redis_proxy/proxy_filter.h
+++ b/source/extensions/filters/network/redis_proxy/proxy_filter.h
@@ -75,7 +75,7 @@ class ProxyFilter : public Network::ReadFilter,
 public:
   ProxyFilter(Common::Redis::DecoderFactory& factory, Common::Redis::EncoderPtr&& encoder,
               CommandSplitter::Instance& splitter, ProxyFilterConfigSharedPtr config);
-  ~ProxyFilter();
+  ~ProxyFilter() override;
 
   // Network::ReadFilter
   void initializeReadFilterCallbacks(Network::ReadFilterCallbacks& callbacks) override;
@@ -95,7 +95,7 @@ class ProxyFilter : public Network::ReadFilter,
 private:
   struct PendingRequest : public CommandSplitter::SplitCallbacks {
     PendingRequest(ProxyFilter& parent);
-    ~PendingRequest();
+    ~PendingRequest() override;
 
     // RedisProxy::CommandSplitter::SplitCallbacks
     bool connectionAllowed() override { return parent_.connectionAllowed(); }
diff --git a/source/extensions/filters/network/thrift_proxy/conn_manager.h b/source/extensions/filters/network/thrift_proxy/conn_manager.h
index afdcbcc8ff34..2188ad7ee9eb 100644
--- a/source/extensions/filters/network/thrift_proxy/conn_manager.h
+++ b/source/extensions/filters/network/thrift_proxy/conn_manager.h
@@ -61,7 +61,7 @@ class ConnectionManager : public Network::ReadFilter,
 public:
   ConnectionManager(Config& config, Runtime::RandomGenerator& random_generator,
                     TimeSource& time_system);
-  ~ConnectionManager();
+  ~ConnectionManager() override;
 
   // Network::ReadFilter
   Network::FilterStatus onData(Buffer::Instance& data, bool end_stream) override;
@@ -164,7 +164,7 @@ class ConnectionManager : public Network::ReadFilter,
       stream_info_.setDownstreamRemoteAddress(
           parent_.read_callbacks_->connection().remoteAddress());
     }
-    ~ActiveRpc() {
+    ~ActiveRpc() override {
       request_timer_->complete();
       parent_.stats_.request_active_.dec();
 
diff --git a/source/extensions/filters/network/thrift_proxy/thrift_object_impl.h b/source/extensions/filters/network/thrift_proxy/thrift_object_impl.h
index 39c31b3c79a0..d6961ce87357 100644
--- a/source/extensions/filters/network/thrift_proxy/thrift_object_impl.h
+++ b/source/extensions/filters/network/thrift_proxy/thrift_object_impl.h
@@ -18,7 +18,7 @@ namespace ThriftProxy {
 class ThriftBase : public DecoderEventHandler {
 public:
   ThriftBase(ThriftBase* parent);
-  ~ThriftBase() = default;
+  ~ThriftBase() override = default;
 
   // DecoderEventHandler
   FilterStatus transportBegin(MessageMetadataSharedPtr) override { return FilterStatus::Continue; }
@@ -61,7 +61,7 @@ class ThriftValueBase : public ThriftValue, public ThriftBase {
 public:
   ThriftValueBase(ThriftBase* parent, FieldType value_type)
       : ThriftBase(parent), value_type_(value_type) {}
-  ~ThriftValueBase() = default;
+  ~ThriftValueBase() override = default;
 
   // ThriftValue
   FieldType type() const override { return value_type_; }
diff --git a/source/extensions/grpc_credentials/example/config.h b/source/extensions/grpc_credentials/example/config.h
index 06f2d2f2b498..f10557a30a55 100644
--- a/source/extensions/grpc_credentials/example/config.h
+++ b/source/extensions/grpc_credentials/example/config.h
@@ -27,7 +27,7 @@ namespace Example {
  */
 class AccessTokenExampleGrpcCredentialsFactory : public Grpc::GoogleGrpcCredentialsFactory {
 public:
-  virtual std::shared_ptr<grpc::ChannelCredentials>
+  std::shared_ptr<grpc::ChannelCredentials>
   getChannelCredentials(const envoy::api::v2::core::GrpcService& grpc_service_config,
                         Api::Api& api) override;
 
diff --git a/source/extensions/health_checkers/redis/redis.h b/source/extensions/health_checkers/redis/redis.h
index 63f9dd0de0d5..346b27e9b951 100644
--- a/source/extensions/health_checkers/redis/redis.h
+++ b/source/extensions/health_checkers/redis/redis.h
@@ -51,7 +51,7 @@ class RedisHealthChecker : public Upstream::HealthCheckerImplBase {
         public Extensions::NetworkFilters::Common::Redis::Client::PoolCallbacks,
         public Network::ConnectionCallbacks {
     RedisActiveHealthCheckSession(RedisHealthChecker& parent, const Upstream::HostSharedPtr& host);
-    ~RedisActiveHealthCheckSession();
+    ~RedisActiveHealthCheckSession() override;
 
     // ActiveHealthCheckSession
     void onInterval() override;
diff --git a/source/extensions/stat_sinks/common/statsd/statsd.h b/source/extensions/stat_sinks/common/statsd/statsd.h
index a13cd0a730bc..a6eb91a62750 100644
--- a/source/extensions/stat_sinks/common/statsd/statsd.h
+++ b/source/extensions/stat_sinks/common/statsd/statsd.h
@@ -30,7 +30,7 @@ class Writer : public ThreadLocal::ThreadLocalObject {
   Writer(Network::Address::InstanceConstSharedPtr address);
   // For testing.
   Writer() : io_handle_(std::make_unique<Network::IoSocketHandleImpl>()) {}
-  virtual ~Writer();
+  ~Writer() override;
 
   virtual void write(const std::string& message);
   // Called in unit test to validate address.
@@ -98,7 +98,7 @@ class TcpStatsdSink : public Stats::Sink {
 private:
   struct TlsSink : public ThreadLocal::ThreadLocalObject, public Network::ConnectionCallbacks {
     TlsSink(TcpStatsdSink& parent, Event::Dispatcher& dispatcher);
-    ~TlsSink();
+    ~TlsSink() override;
 
     void beginFlush(bool expect_empty_buffer);
     void checkSize();
diff --git a/source/extensions/tracers/common/factory_base.h b/source/extensions/tracers/common/factory_base.h
index 67191834c65b..6b57de7b3c35 100644
--- a/source/extensions/tracers/common/factory_base.h
+++ b/source/extensions/tracers/common/factory_base.h
@@ -15,8 +15,8 @@ namespace Common {
 template <class ConfigProto> class FactoryBase : public Server::Configuration::TracerFactory {
 public:
   // Server::Configuration::TracerFactory
-  virtual Tracing::HttpTracerPtr createHttpTracer(const Protobuf::Message& config,
-                                                  Server::Instance& server) override {
+  Tracing::HttpTracerPtr createHttpTracer(const Protobuf::Message& config,
+                                          Server::Instance& server) override {
     return createHttpTracerTyped(MessageUtil::downcastAndValidate<const ConfigProto&>(config),
                                  server);
   }
diff --git a/source/extensions/tracers/lightstep/lightstep_tracer_impl.h b/source/extensions/tracers/lightstep/lightstep_tracer_impl.h
index d6046ccd4e40..6988ce504bcc 100644
--- a/source/extensions/tracers/lightstep/lightstep_tracer_impl.h
+++ b/source/extensions/tracers/lightstep/lightstep_tracer_impl.h
@@ -74,7 +74,7 @@ class LightStepDriver : public Common::Ot::OpenTracingDriver {
   public:
     explicit LightStepTransporter(LightStepDriver& driver);
 
-    ~LightStepTransporter();
+    ~LightStepTransporter() override;
 
     // lightstep::AsyncTransporter
     void Send(const Protobuf::Message& request, Protobuf::Message& response,
diff --git a/source/extensions/transport_sockets/alts/config.cc b/source/extensions/transport_sockets/alts/config.cc
index 1549a2a33d77..a85bb9d7fa85 100644
--- a/source/extensions/transport_sockets/alts/config.cc
+++ b/source/extensions/transport_sockets/alts/config.cc
@@ -64,7 +64,7 @@ class AltsSharedState : public Singleton::Instance {
 public:
   AltsSharedState() { grpc_alts_shared_resource_dedicated_init(); }
 
-  ~AltsSharedState() { grpc_alts_shared_resource_dedicated_shutdown(); }
+  ~AltsSharedState() override { grpc_alts_shared_resource_dedicated_shutdown(); }
 };
 
 SINGLETON_MANAGER_REGISTRATION(alts_shared_state);
diff --git a/source/extensions/transport_sockets/alts/tsi_handshaker.h b/source/extensions/transport_sockets/alts/tsi_handshaker.h
index d578493573ec..71cd6989e71a 100644
--- a/source/extensions/transport_sockets/alts/tsi_handshaker.h
+++ b/source/extensions/transport_sockets/alts/tsi_handshaker.h
@@ -51,7 +51,7 @@ class TsiHandshakerCallbacks {
 class TsiHandshaker final : public Event::DeferredDeletable {
 public:
   explicit TsiHandshaker(CHandshakerPtr&& handshaker, Event::Dispatcher& dispatcher);
-  ~TsiHandshaker();
+  ~TsiHandshaker() override;
 
   /**
    * Conduct next step of handshake, see
diff --git a/source/extensions/transport_sockets/alts/tsi_socket.h b/source/extensions/transport_sockets/alts/tsi_socket.h
index 31b4571db096..bbd7b19fadcb 100644
--- a/source/extensions/transport_sockets/alts/tsi_socket.h
+++ b/source/extensions/transport_sockets/alts/tsi_socket.h
@@ -51,7 +51,7 @@ class TsiSocket : public Network::TransportSocket,
    * The connection will be closed immediately if it returns false.
    */
   TsiSocket(HandshakerFactory handshaker_factory, HandshakeValidator handshake_validator);
-  virtual ~TsiSocket();
+  ~TsiSocket() override;
 
   // Network::TransportSocket
   void setTransportSocketCallbacks(Envoy::Network::TransportSocketCallbacks& callbacks) override;
diff --git a/source/extensions/transport_sockets/tls/context_manager_impl.h b/source/extensions/transport_sockets/tls/context_manager_impl.h
index 2bb82342940c..88ef9e67d546 100644
--- a/source/extensions/transport_sockets/tls/context_manager_impl.h
+++ b/source/extensions/transport_sockets/tls/context_manager_impl.h
@@ -22,7 +22,7 @@ namespace Tls {
 class ContextManagerImpl final : public Envoy::Ssl::ContextManager {
 public:
   ContextManagerImpl(TimeSource& time_source) : time_source_(time_source) {}
-  ~ContextManagerImpl();
+  ~ContextManagerImpl() override;
 
   // Ssl::ContextManager
   Ssl::ClientContextSharedPtr
diff --git a/source/server/config_validation/connection.h b/source/server/config_validation/connection.h
index 7c6d5b6db062..6fb9839ff890 100644
--- a/source/server/config_validation/connection.h
+++ b/source/server/config_validation/connection.h
@@ -24,7 +24,7 @@ class ConfigValidateConnection : public Network::ClientConnectionImpl {
 
   // Unit tests may instantiate it without proper event machine and leave opened sockets.
   // Do some cleanup before invoking base class's destructor.
-  virtual ~ConfigValidateConnection() { close(ConnectionCloseType::NoFlush); }
+  ~ConfigValidateConnection() override { close(ConnectionCloseType::NoFlush); }
 
   // connect may be called in config verification mode.
   // It is redefined as no-op. Calling parent's method triggers connection to upstream host.
diff --git a/source/server/http/config_tracker_impl.h b/source/server/http/config_tracker_impl.h
index 0bcb840b7478..3c8ab1c156bf 100644
--- a/source/server/http/config_tracker_impl.h
+++ b/source/server/http/config_tracker_impl.h
@@ -22,7 +22,7 @@ class ConfigTrackerImpl : public ConfigTracker {
   class EntryOwnerImpl : public ConfigTracker::EntryOwner {
   public:
     EntryOwnerImpl(const std::shared_ptr<CbsMap>& map, const std::string& key);
-    ~EntryOwnerImpl();
+    ~EntryOwnerImpl() override;
 
   private:
     std::shared_ptr<CbsMap> map_;
diff --git a/source/server/listener_manager_impl.h b/source/server/listener_manager_impl.h
index c3c9055ae4fd..43edef1e2f3e 100644
--- a/source/server/listener_manager_impl.h
+++ b/source/server/listener_manager_impl.h
@@ -226,7 +226,7 @@ class ListenerImpl : public Network::ListenerConfig,
   ListenerImpl(const envoy::api::v2::Listener& config, const std::string& version_info,
                ListenerManagerImpl& parent, const std::string& name, bool modifiable,
                bool workers_started, uint64_t hash);
-  ~ListenerImpl();
+  ~ListenerImpl() override;
 
   /**
    * Helper functions to determine whether a listener is blocked for update or remove.
diff --git a/source/server/options_impl.h b/source/server/options_impl.h
index cddf660f79f4..3269050f5fc4 100644
--- a/source/server/options_impl.h
+++ b/source/server/options_impl.h
@@ -103,7 +103,7 @@ class OptionsImpl : public Server::Options, protected Logger::Loggable<Logger::I
   bool signalHandlingEnabled() const override { return signal_handling_enabled_; }
   bool mutexTracingEnabled() const override { return mutex_tracing_enabled_; }
   bool libeventBufferEnabled() const override { return libevent_buffer_enabled_; }
-  virtual Server::CommandLineOptionsPtr toCommandLineOptions() const override;
+  Server::CommandLineOptionsPtr toCommandLineOptions() const override;
   void parseComponentLogLevels(const std::string& component_log_levels);
   bool cpusetThreadsEnabled() const override { return cpuset_threads_; }
   uint32_t count() const;
diff --git a/source/server/overload_manager_impl.cc b/source/server/overload_manager_impl.cc
index 8de9f2ac61b5..6eaad4b82c9b 100644
--- a/source/server/overload_manager_impl.cc
+++ b/source/server/overload_manager_impl.cc
@@ -20,13 +20,13 @@ class ThresholdTriggerImpl : public OverloadAction::Trigger {
   ThresholdTriggerImpl(const envoy::config::overload::v2alpha::ThresholdTrigger& config)
       : threshold_(config.value()) {}
 
-  bool updateValue(double value) {
+  bool updateValue(double value) override {
     const bool fired = isFired();
     value_ = value;
     return fired != isFired();
   }
 
-  bool isFired() const { return value_.has_value() && value_ >= threshold_; }
+  bool isFired() const override { return value_.has_value() && value_ >= threshold_; }
 
 private:
   const double threshold_;
diff --git a/test/common/config/delta_subscription_test_harness.h b/test/common/config/delta_subscription_test_harness.h
index e14599210884..a2431c154bc8 100644
--- a/test/common/config/delta_subscription_test_harness.h
+++ b/test/common/config/delta_subscription_test_harness.h
@@ -38,7 +38,7 @@ class DeltaSubscriptionTestHarness : public SubscriptionTestHarness {
         rate_limit_settings_, callbacks_, stats_, init_fetch_timeout);
   }
 
-  ~DeltaSubscriptionTestHarness() {
+  ~DeltaSubscriptionTestHarness() override {
     while (!nonce_acks_required_.empty()) {
       EXPECT_FALSE(nonce_acks_sent_.empty());
       EXPECT_EQ(nonce_acks_required_.front(), nonce_acks_sent_.front());
diff --git a/test/common/config/filesystem_subscription_test_harness.h b/test/common/config/filesystem_subscription_test_harness.h
index 9a14fc73dd5c..28dea555e0d5 100644
--- a/test/common/config/filesystem_subscription_test_harness.h
+++ b/test/common/config/filesystem_subscription_test_harness.h
@@ -32,7 +32,7 @@ class FilesystemSubscriptionTestHarness : public SubscriptionTestHarness {
         api_(Api::createApiForTest(stats_store_)), dispatcher_(api_->allocateDispatcher()),
         subscription_(*dispatcher_, path_, callbacks_, stats_, validation_visitor_, *api_) {}
 
-  ~FilesystemSubscriptionTestHarness() {
+  ~FilesystemSubscriptionTestHarness() override {
     if (::access(path_.c_str(), F_OK) != -1) {
       EXPECT_EQ(0, ::unlink(path_.c_str()));
     }
diff --git a/test/common/config/http_subscription_test_harness.h b/test/common/config/http_subscription_test_harness.h
index c769a40cc4ff..ecf5c056950e 100644
--- a/test/common/config/http_subscription_test_harness.h
+++ b/test/common/config/http_subscription_test_harness.h
@@ -51,7 +51,7 @@ class HttpSubscriptionTestHarness : public SubscriptionTestHarness {
         init_fetch_timeout, validation_visitor_);
   }
 
-  ~HttpSubscriptionTestHarness() {
+  ~HttpSubscriptionTestHarness() override {
     // Stop subscribing on the way out.
     if (request_in_progress_) {
       EXPECT_CALL(http_request_, cancel());
diff --git a/test/common/config/metadata_test.cc b/test/common/config/metadata_test.cc
index 28d5cb67b4a8..885d69f82117 100644
--- a/test/common/config/metadata_test.cc
+++ b/test/common/config/metadata_test.cc
@@ -61,9 +61,10 @@ class TypedMetadataTest : public testing::Test {
 
   class FooFactory : public TypedMetadataFactory::TypedMetadataFactory {
   public:
-    const std::string name() const { return "foo"; }
+    const std::string name() const override { return "foo"; }
     // Throws EnvoyException (conversion failure) if d is empty.
-    std::unique_ptr<const TypedMetadata::Object> parse(const ProtobufWkt::Struct& d) const {
+    std::unique_ptr<const TypedMetadata::Object>
+    parse(const ProtobufWkt::Struct& d) const override {
       if (d.fields().find("name") != d.fields().end()) {
         return std::make_unique<Foo>(d.fields().at("name").string_value());
       }
diff --git a/test/common/event/dispatcher_impl_test.cc b/test/common/event/dispatcher_impl_test.cc
index 97a36cc43c03..b6fc1de1b124 100644
--- a/test/common/event/dispatcher_impl_test.cc
+++ b/test/common/event/dispatcher_impl_test.cc
@@ -28,7 +28,7 @@ namespace {
 class TestDeferredDeletable : public DeferredDeletable {
 public:
   TestDeferredDeletable(std::function<void()> on_destroy) : on_destroy_(on_destroy) {}
-  ~TestDeferredDeletable() { on_destroy_(); }
+  ~TestDeferredDeletable() override { on_destroy_(); }
 
 private:
   std::function<void()> on_destroy_;
diff --git a/test/common/grpc/grpc_client_integration_test.cc b/test/common/grpc/grpc_client_integration_test.cc
index 5044cace4d40..f7b7505b4ad8 100644
--- a/test/common/grpc/grpc_client_integration_test.cc
+++ b/test/common/grpc/grpc_client_integration_test.cc
@@ -406,7 +406,7 @@ class GrpcAccessTokenClientIntegrationTest : public GrpcSslClientIntegrationTest
     }
   }
 
-  virtual envoy::api::v2::core::GrpcService createGoogleGrpcConfig() override {
+  envoy::api::v2::core::GrpcService createGoogleGrpcConfig() override {
     auto config = GrpcClientIntegrationTest::createGoogleGrpcConfig();
     auto* google_grpc = config.mutable_google_grpc();
     google_grpc->set_credentials_factory_name(credentials_factory_name_);
diff --git a/test/common/grpc/grpc_client_integration_test_harness.h b/test/common/grpc/grpc_client_integration_test_harness.h
index ad8a997d770b..997bae8b6bb8 100644
--- a/test/common/grpc/grpc_client_integration_test_harness.h
+++ b/test/common/grpc/grpc_client_integration_test_harness.h
@@ -471,7 +471,7 @@ class GrpcSslClientIntegrationTest : public GrpcClientIntegrationTest {
     mock_cluster_info_->transport_socket_factory_.reset();
   }
 
-  virtual envoy::api::v2::core::GrpcService createGoogleGrpcConfig() override {
+  envoy::api::v2::core::GrpcService createGoogleGrpcConfig() override {
     auto config = GrpcClientIntegrationTest::createGoogleGrpcConfig();
     TestUtility::setTestSslGoogleGrpcConfig(config, use_client_cert_);
     return config;
diff --git a/test/common/http/codec_client_test.cc b/test/common/http/codec_client_test.cc
index 911b8a64c55f..7fc083eba090 100644
--- a/test/common/http/codec_client_test.cc
+++ b/test/common/http/codec_client_test.cc
@@ -58,7 +58,7 @@ class CodecClientTest : public testing::Test {
                                                    dispatcher_);
   }
 
-  ~CodecClientTest() { EXPECT_EQ(0U, client_->numActiveRequests()); }
+  ~CodecClientTest() override { EXPECT_EQ(0U, client_->numActiveRequests()); }
 
   Event::MockDispatcher dispatcher_;
   Network::MockClientConnection* connection_;
diff --git a/test/common/http/common.h b/test/common/http/common.h
index e2c4d4a5e12c..9aa57ef87c8e 100644
--- a/test/common/http/common.h
+++ b/test/common/http/common.h
@@ -24,7 +24,7 @@ class CodecClientForTest : public Http::CodecClient {
         destroy_cb_(destroy_cb) {
     codec_.reset(codec);
   }
-  ~CodecClientForTest() {
+  ~CodecClientForTest() override {
     if (destroy_cb_) {
       destroy_cb_(this);
     }
diff --git a/test/common/http/conn_manager_impl_test.cc b/test/common/http/conn_manager_impl_test.cc
index 31865f3f7287..7f2abde9ba58 100644
--- a/test/common/http/conn_manager_impl_test.cc
+++ b/test/common/http/conn_manager_impl_test.cc
@@ -89,7 +89,7 @@ class HttpConnectionManagerImplTest : public testing::Test, public ConnectionMan
     EXPECT_CALL(response_encoder_, getStream()).Times(AtLeast(0));
   }
 
-  ~HttpConnectionManagerImplTest() {
+  ~HttpConnectionManagerImplTest() override {
     filter_callbacks_.connection_.dispatcher_.clearDeferredDeleteList();
   }
 
diff --git a/test/common/http/http1/conn_pool_test.cc b/test/common/http/http1/conn_pool_test.cc
index 002aecc3ce52..df25c3ee3bf5 100644
--- a/test/common/http/http1/conn_pool_test.cc
+++ b/test/common/http/http1/conn_pool_test.cc
@@ -50,7 +50,7 @@ class ConnPoolImplForTest : public ConnPoolImpl {
         api_(Api::createApiForTest()), mock_dispatcher_(dispatcher),
         mock_upstream_ready_timer_(upstream_ready_timer) {}
 
-  ~ConnPoolImplForTest() {
+  ~ConnPoolImplForTest() override {
     EXPECT_EQ(0U, ready_clients_.size());
     EXPECT_EQ(0U, busy_clients_.size());
     EXPECT_EQ(0U, pending_requests_.size());
@@ -128,7 +128,7 @@ class Http1ConnPoolImplTest : public testing::Test {
       : upstream_ready_timer_(new NiceMock<Event::MockTimer>(&dispatcher_)),
         conn_pool_(dispatcher_, cluster_, upstream_ready_timer_) {}
 
-  ~Http1ConnPoolImplTest() {
+  ~Http1ConnPoolImplTest() override {
     EXPECT_TRUE(TestUtility::gaugesZeroed(cluster_->stats_store_.gauges()));
   }
 
diff --git a/test/common/http/http2/conn_pool_test.cc b/test/common/http/http2/conn_pool_test.cc
index b63d04c9afa5..9a17581301c7 100644
--- a/test/common/http/http2/conn_pool_test.cc
+++ b/test/common/http/http2/conn_pool_test.cc
@@ -67,7 +67,7 @@ class Http2ConnPoolImplTest : public testing::Test {
       : api_(Api::createApiForTest(stats_store_)),
         pool_(dispatcher_, host_, Upstream::ResourcePriority::Default, nullptr) {}
 
-  ~Http2ConnPoolImplTest() {
+  ~Http2ConnPoolImplTest() override {
     EXPECT_TRUE(TestUtility::gaugesZeroed(cluster_->stats_store_.gauges()));
   }
 
diff --git a/test/common/network/connection_impl_test.cc b/test/common/network/connection_impl_test.cc
index dd7f751d55ed..0526b0ec97dc 100644
--- a/test/common/network/connection_impl_test.cc
+++ b/test/common/network/connection_impl_test.cc
@@ -1336,21 +1336,23 @@ TEST_P(ConnectionImplTest, DelayedCloseTimeoutNullStats) {
 class FakeReadFilter : public Network::ReadFilter {
 public:
   FakeReadFilter() = default;
-  ~FakeReadFilter() {
+  ~FakeReadFilter() override {
     EXPECT_TRUE(callbacks_ != nullptr);
     // The purpose is to verify that when FilterManger is destructed, ConnectionSocketImpl is not
     // destructed, and ConnectionSocketImpl can still be accessed via ReadFilterCallbacks.
     EXPECT_TRUE(callbacks_->connection().state() != Network::Connection::State::Open);
   }
 
-  Network::FilterStatus onData(Buffer::Instance& data, bool) {
+  Network::FilterStatus onData(Buffer::Instance& data, bool) override {
     data.drain(data.length());
     return Network::FilterStatus::Continue;
   }
 
-  Network::FilterStatus onNewConnection() { return Network::FilterStatus::Continue; }
+  Network::FilterStatus onNewConnection() override { return Network::FilterStatus::Continue; }
 
-  void initializeReadFilterCallbacks(ReadFilterCallbacks& callbacks) { callbacks_ = &callbacks; }
+  void initializeReadFilterCallbacks(ReadFilterCallbacks& callbacks) override {
+    callbacks_ = &callbacks;
+  }
 
 private:
   ReadFilterCallbacks* callbacks_{nullptr};
@@ -1380,7 +1382,7 @@ class MockTransportConnectionImplTest : public testing::Test {
     connection_->addConnectionCallbacks(callbacks_);
   }
 
-  ~MockTransportConnectionImplTest() { connection_->close(ConnectionCloseType::NoFlush); }
+  ~MockTransportConnectionImplTest() override { connection_->close(ConnectionCloseType::NoFlush); }
 
   // This may be invoked for doWrite() on the transport to simulate all the data
   // being written.
diff --git a/test/common/network/filter_manager_impl_test.cc b/test/common/network/filter_manager_impl_test.cc
index cccbac597e73..f713a79a63e3 100644
--- a/test/common/network/filter_manager_impl_test.cc
+++ b/test/common/network/filter_manager_impl_test.cc
@@ -56,7 +56,7 @@ class NetworkFilterManagerTest : public testing::Test {
 
 class LocalMockFilter : public MockFilter {
 public:
-  ~LocalMockFilter() {
+  ~LocalMockFilter() override {
     // Make sure the upstream host is still valid in the filter destructor.
     callbacks_->upstreamHost()->address();
   }
diff --git a/test/common/router/config_impl_test.cc b/test/common/router/config_impl_test.cc
index 755ef68d98d9..5af81cbc1ff9 100644
--- a/test/common/router/config_impl_test.cc
+++ b/test/common/router/config_impl_test.cc
@@ -3521,10 +3521,10 @@ struct Baz : public Envoy::Config::TypedMetadata::Object {
 };
 class BazFactory : public HttpRouteTypedMetadataFactory {
 public:
-  const std::string name() const { return "baz"; }
+  const std::string name() const override { return "baz"; }
   // Returns nullptr (conversion failure) if d is empty.
   std::unique_ptr<const Envoy::Config::TypedMetadata::Object>
-  parse(const ProtobufWkt::Struct& d) const {
+  parse(const ProtobufWkt::Struct& d) const override {
     if (d.fields().find("name") != d.fields().end()) {
       return std::make_unique<Baz>(d.fields().at("name").string_value());
     }
diff --git a/test/common/router/rds_impl_test.cc b/test/common/router/rds_impl_test.cc
index daa93436b370..303589eb9750 100644
--- a/test/common/router/rds_impl_test.cc
+++ b/test/common/router/rds_impl_test.cc
@@ -75,7 +75,7 @@ class RdsImplTest : public RdsTestBase {
     route_config_provider_manager_ =
         std::make_unique<RouteConfigProviderManagerImpl>(factory_context_.admin_);
   }
-  ~RdsImplTest() { factory_context_.thread_local_.shutdownThread(); }
+  ~RdsImplTest() override { factory_context_.thread_local_.shutdownThread(); }
 
   void setup() {
     const std::string config_json = R"EOF(
@@ -276,7 +276,9 @@ class RouteConfigProviderManagerImplTest : public RdsTestBase {
         std::make_unique<RouteConfigProviderManagerImpl>(factory_context_.admin_);
   }
 
-  ~RouteConfigProviderManagerImplTest() { factory_context_.thread_local_.shutdownThread(); }
+  ~RouteConfigProviderManagerImplTest() override {
+    factory_context_.thread_local_.shutdownThread();
+  }
 
   envoy::config::filter::network::http_connection_manager::v2::Rds rds_;
   std::unique_ptr<RouteConfigProviderManagerImpl> route_config_provider_manager_;
diff --git a/test/common/secret/sds_api_test.cc b/test/common/secret/sds_api_test.cc
index ae59bf16a54c..5db20fa89e3b 100644
--- a/test/common/secret/sds_api_test.cc
+++ b/test/common/secret/sds_api_test.cc
@@ -241,7 +241,7 @@ class CvcValidationCallback {
 class MockCvcValidationCallback : public CvcValidationCallback {
 public:
   MockCvcValidationCallback() = default;
-  ~MockCvcValidationCallback() = default;
+  ~MockCvcValidationCallback() override = default;
   MOCK_METHOD1(validateCvc, void(const envoy::api::v2::auth::CertificateValidationContext&));
 };
 
diff --git a/test/common/signal/signals_test.cc b/test/common/signal/signals_test.cc
index 0dda4fe752c8..98753f047d0f 100644
--- a/test/common/signal/signals_test.cc
+++ b/test/common/signal/signals_test.cc
@@ -36,7 +36,7 @@ TEST(SignalsDeathTest, InvalidAddressDeathTest) {
 }
 
 class TestFatalErrorHandler : public FatalErrorHandlerInterface {
-  virtual void onFatalError() const override { std::cerr << "HERE!"; }
+  void onFatalError() const override { std::cerr << "HERE!"; }
 };
 
 TEST(SignalsDeathTest, RegisteredHandlerTest) {
diff --git a/test/common/singleton/manager_impl_test.cc b/test/common/singleton/manager_impl_test.cc
index 14b3d9eacad2..95b3b768a151 100644
--- a/test/common/singleton/manager_impl_test.cc
+++ b/test/common/singleton/manager_impl_test.cc
@@ -29,7 +29,7 @@ static Registry::RegisterFactory<Singleton::RegistrationImpl<test_singleton_name
 
 class TestSingleton : public Instance {
 public:
-  ~TestSingleton() { onDestroy(); }
+  ~TestSingleton() override { onDestroy(); }
 
   MOCK_METHOD0(onDestroy, void());
 };
diff --git a/test/common/singleton/threadsafe_singleton_test.cc b/test/common/singleton/threadsafe_singleton_test.cc
index 4877425735c5..a6dba199526e 100644
--- a/test/common/singleton/threadsafe_singleton_test.cc
+++ b/test/common/singleton/threadsafe_singleton_test.cc
@@ -34,7 +34,7 @@ class TestSingleton {
 class EvilMathSingleton : public TestSingleton {
 public:
   EvilMathSingleton() { value_ = -50; }
-  virtual void addOne() {
+  void addOne() override {
     Thread::LockGuard lock(lock_);
     ++value_;
     ++value_;
diff --git a/test/common/stats/allocator_impl_test.cc b/test/common/stats/allocator_impl_test.cc
index 99327899f2a6..37339b138478 100644
--- a/test/common/stats/allocator_impl_test.cc
+++ b/test/common/stats/allocator_impl_test.cc
@@ -14,7 +14,7 @@ namespace {
 class AllocatorImplTest : public testing::Test {
 protected:
   AllocatorImplTest() : alloc_(symbol_table_), pool_(symbol_table_) {}
-  ~AllocatorImplTest() { clearStorage(); }
+  ~AllocatorImplTest() override { clearStorage(); }
 
   StatNameStorage makeStatStorage(absl::string_view name) {
     return StatNameStorage(name, symbol_table_);
diff --git a/test/common/stats/metric_impl_test.cc b/test/common/stats/metric_impl_test.cc
index ed3a10abd537..16e90a220199 100644
--- a/test/common/stats/metric_impl_test.cc
+++ b/test/common/stats/metric_impl_test.cc
@@ -15,7 +15,7 @@ namespace {
 class MetricImplTest : public testing::Test {
 protected:
   MetricImplTest() : alloc_(symbol_table_), pool_(symbol_table_) {}
-  ~MetricImplTest() { clearStorage(); }
+  ~MetricImplTest() override { clearStorage(); }
 
   StatName makeStat(absl::string_view name) { return pool_.add(name); }
 
diff --git a/test/common/stream_info/filter_state_impl_test.cc b/test/common/stream_info/filter_state_impl_test.cc
index 56fbbd91d00d..4cf7ab250881 100644
--- a/test/common/stream_info/filter_state_impl_test.cc
+++ b/test/common/stream_info/filter_state_impl_test.cc
@@ -14,7 +14,7 @@ class TestStoredTypeTracking : public FilterState::Object {
 public:
   TestStoredTypeTracking(int value, size_t* access_count, size_t* destruction_count)
       : value_(value), access_count_(access_count), destruction_count_(destruction_count) {}
-  ~TestStoredTypeTracking() {
+  ~TestStoredTypeTracking() override {
     if (destruction_count_) {
       ++*destruction_count_;
     }
diff --git a/test/common/tcp/conn_pool_test.cc b/test/common/tcp/conn_pool_test.cc
index 68153686e52b..5cf14a40a0f5 100644
--- a/test/common/tcp/conn_pool_test.cc
+++ b/test/common/tcp/conn_pool_test.cc
@@ -34,7 +34,7 @@ namespace {
 struct TestConnectionState : public ConnectionPool::ConnectionState {
   TestConnectionState(int id, std::function<void()> on_destructor)
       : id_(id), on_destructor_(on_destructor) {}
-  ~TestConnectionState() { on_destructor_(); }
+  ~TestConnectionState() override { on_destructor_(); }
 
   int id_;
   std::function<void()> on_destructor_;
@@ -79,7 +79,7 @@ class ConnPoolImplForTest : public ConnPoolImpl {
                      Upstream::ResourcePriority::Default, nullptr, nullptr),
         mock_dispatcher_(dispatcher), mock_upstream_ready_timer_(upstream_ready_timer) {}
 
-  ~ConnPoolImplForTest() {
+  ~ConnPoolImplForTest() override {
     EXPECT_EQ(0U, ready_conns_.size());
     EXPECT_EQ(0U, busy_conns_.size());
     EXPECT_EQ(0U, pending_requests_.size());
@@ -158,7 +158,7 @@ class TcpConnPoolImplTest : public testing::Test {
       : upstream_ready_timer_(new NiceMock<Event::MockTimer>(&dispatcher_)),
         conn_pool_(dispatcher_, cluster_, upstream_ready_timer_) {}
 
-  ~TcpConnPoolImplTest() {
+  ~TcpConnPoolImplTest() override {
     EXPECT_TRUE(TestUtility::gaugesZeroed(cluster_->stats_store_.gauges()));
   }
 
@@ -180,7 +180,7 @@ class TcpConnPoolImplDestructorTest : public testing::Test {
                                     Upstream::makeTestHost(cluster_, "tcp://127.0.0.1:9000"),
                                     Upstream::ResourcePriority::Default, nullptr, nullptr)} {}
 
-  ~TcpConnPoolImplDestructorTest() = default;
+  ~TcpConnPoolImplDestructorTest() override = default;
 
   void prepareConn() {
     connection_ = new NiceMock<Network::MockClientConnection>();
diff --git a/test/common/tcp_proxy/tcp_proxy_test.cc b/test/common/tcp_proxy/tcp_proxy_test.cc
index ec747aa3dca3..dbfb840d619c 100644
--- a/test/common/tcp_proxy/tcp_proxy_test.cc
+++ b/test/common/tcp_proxy/tcp_proxy_test.cc
@@ -357,7 +357,7 @@ class TcpProxyTest : public testing::Test {
         .WillByDefault(SaveArg<0>(&access_log_data_));
   }
 
-  ~TcpProxyTest() {
+  ~TcpProxyTest() override {
     if (filter_ != nullptr) {
       filter_callbacks_.connection_.raiseEvent(Network::ConnectionEvent::RemoteClose);
     }
diff --git a/test/common/thread_local/thread_local_impl_test.cc b/test/common/thread_local/thread_local_impl_test.cc
index 49ba114a2daf..5a678c839384 100644
--- a/test/common/thread_local/thread_local_impl_test.cc
+++ b/test/common/thread_local/thread_local_impl_test.cc
@@ -18,7 +18,7 @@ namespace {
 
 class TestThreadLocalObject : public ThreadLocalObject {
 public:
-  ~TestThreadLocalObject() { onDestroy(); }
+  ~TestThreadLocalObject() override { onDestroy(); }
 
   MOCK_METHOD0(onDestroy, void());
 };
diff --git a/test/common/upstream/cluster_manager_impl_test.cc b/test/common/upstream/cluster_manager_impl_test.cc
index e9aa3293d89a..039490906a11 100644
--- a/test/common/upstream/cluster_manager_impl_test.cc
+++ b/test/common/upstream/cluster_manager_impl_test.cc
@@ -2130,14 +2130,14 @@ TEST_F(ClusterManagerImplTest, DynamicHostRemoveDefaultPriority) {
 
 class MockConnPoolWithDestroy : public Http::ConnectionPool::MockInstance {
 public:
-  ~MockConnPoolWithDestroy() { onDestroy(); }
+  ~MockConnPoolWithDestroy() override { onDestroy(); }
 
   MOCK_METHOD0(onDestroy, void());
 };
 
 class MockTcpConnPoolWithDestroy : public Tcp::ConnectionPool::MockInstance {
 public:
-  ~MockTcpConnPoolWithDestroy() { onDestroy(); }
+  ~MockTcpConnPoolWithDestroy() override { onDestroy(); }
 
   MOCK_METHOD0(onDestroy, void());
 };
diff --git a/test/common/upstream/upstream_impl_test.cc b/test/common/upstream/upstream_impl_test.cc
index b0b8094c55b2..688e53b06e7b 100644
--- a/test/common/upstream/upstream_impl_test.cc
+++ b/test/common/upstream/upstream_impl_test.cc
@@ -1872,10 +1872,10 @@ struct Baz : public Envoy::Config::TypedMetadata::Object {
 
 class BazFactory : public ClusterTypedMetadataFactory {
 public:
-  const std::string name() const { return "baz"; }
+  const std::string name() const override { return "baz"; }
   // Returns nullptr (conversion failure) if d is empty.
   std::unique_ptr<const Envoy::Config::TypedMetadata::Object>
-  parse(const ProtobufWkt::Struct& d) const {
+  parse(const ProtobufWkt::Struct& d) const override {
     if (d.fields().find("name") != d.fields().end()) {
       return std::make_unique<Baz>(d.fields().at("name").string_value());
     }
diff --git a/test/exe/main_common_test.cc b/test/exe/main_common_test.cc
index baeeb243976a..1d412d13a6e1 100644
--- a/test/exe/main_common_test.cc
+++ b/test/exe/main_common_test.cc
@@ -210,7 +210,7 @@ class AdminRequestTest : public MainCommonTest {
     main_common_->dispatcherForTest().post([this, &done] {
       struct Sacrifice : Event::DeferredDeletable {
         Sacrifice(absl::Notification& notify) : notify_(notify) {}
-        ~Sacrifice() { notify_.Notify(); }
+        ~Sacrifice() override { notify_.Notify(); }
         absl::Notification& notify_;
       };
       auto sacrifice = std::make_unique<Sacrifice>(done);
diff --git a/test/extensions/clusters/redis/mocks.h b/test/extensions/clusters/redis/mocks.h
index 3f4940836f91..7269548b1b2c 100644
--- a/test/extensions/clusters/redis/mocks.h
+++ b/test/extensions/clusters/redis/mocks.h
@@ -15,7 +15,7 @@ namespace Redis {
 class MockClusterSlotUpdateCallBack : public ClusterSlotUpdateCallBack {
 public:
   MockClusterSlotUpdateCallBack();
-  ~MockClusterSlotUpdateCallBack() = default;
+  ~MockClusterSlotUpdateCallBack() override = default;
 
   MOCK_METHOD2(onClusterSlotUpdate, bool(const std::vector<ClusterSlot>&, Upstream::HostMap));
 };
diff --git a/test/extensions/common/dynamic_forward_proxy/dns_cache_impl_test.cc b/test/extensions/common/dynamic_forward_proxy/dns_cache_impl_test.cc
index 3fe6ddad32d3..36ebfec8391c 100644
--- a/test/extensions/common/dynamic_forward_proxy/dns_cache_impl_test.cc
+++ b/test/extensions/common/dynamic_forward_proxy/dns_cache_impl_test.cc
@@ -28,7 +28,7 @@ class DnsCacheImplTest : public testing::Test, public Event::TestUsingSimulatedT
     update_callbacks_handle_ = dns_cache_->addUpdateCallbacks(update_callbacks_);
   }
 
-  ~DnsCacheImplTest() {
+  ~DnsCacheImplTest() override {
     dns_cache_.reset();
     EXPECT_EQ(0, TestUtility::findGauge(store_, "dns_cache.foo.num_hosts")->value());
   }
diff --git a/test/extensions/common/dynamic_forward_proxy/mocks.h b/test/extensions/common/dynamic_forward_proxy/mocks.h
index 0c65895c1f7d..0ac9e476deac 100644
--- a/test/extensions/common/dynamic_forward_proxy/mocks.h
+++ b/test/extensions/common/dynamic_forward_proxy/mocks.h
@@ -12,7 +12,7 @@ namespace DynamicForwardProxy {
 class MockDnsCache : public DnsCache {
 public:
   MockDnsCache();
-  ~MockDnsCache();
+  ~MockDnsCache() override;
 
   struct MockLoadDnsCacheEntryResult {
     LoadDnsCacheEntryStatus status_;
@@ -38,7 +38,7 @@ class MockDnsCache : public DnsCache {
 class MockLoadDnsCacheEntryHandle : public DnsCache::LoadDnsCacheEntryHandle {
 public:
   MockLoadDnsCacheEntryHandle();
-  ~MockLoadDnsCacheEntryHandle();
+  ~MockLoadDnsCacheEntryHandle() override;
 
   MOCK_METHOD0(onDestroy, void());
 };
@@ -46,7 +46,7 @@ class MockLoadDnsCacheEntryHandle : public DnsCache::LoadDnsCacheEntryHandle {
 class MockDnsCacheManager : public DnsCacheManager {
 public:
   MockDnsCacheManager();
-  ~MockDnsCacheManager();
+  ~MockDnsCacheManager() override;
 
   MOCK_METHOD1(
       getCache,
@@ -59,7 +59,7 @@ class MockDnsCacheManager : public DnsCacheManager {
 class MockDnsHostInfo : public DnsHostInfo {
 public:
   MockDnsHostInfo();
-  ~MockDnsHostInfo();
+  ~MockDnsHostInfo() override;
 
   MOCK_METHOD0(address, Network::Address::InstanceConstSharedPtr());
   MOCK_METHOD0(resolvedHost, const std::string&());
@@ -72,7 +72,7 @@ class MockDnsHostInfo : public DnsHostInfo {
 class MockUpdateCallbacks : public DnsCache::UpdateCallbacks {
 public:
   MockUpdateCallbacks();
-  ~MockUpdateCallbacks();
+  ~MockUpdateCallbacks() override;
 
   MOCK_METHOD2(onDnsHostAddOrUpdate,
                void(const std::string& host, const DnsHostInfoSharedPtr& address));
@@ -82,7 +82,7 @@ class MockUpdateCallbacks : public DnsCache::UpdateCallbacks {
 class MockLoadDnsCacheEntryCallbacks : public DnsCache::LoadDnsCacheEntryCallbacks {
 public:
   MockLoadDnsCacheEntryCallbacks();
-  ~MockLoadDnsCacheEntryCallbacks();
+  ~MockLoadDnsCacheEntryCallbacks() override;
 
   MOCK_METHOD0(onLoadDnsCacheComplete, void());
 };
diff --git a/test/extensions/common/tap/admin_test.cc b/test/extensions/common/tap/admin_test.cc
index 8af525043213..4c7428a62820 100644
--- a/test/extensions/common/tap/admin_test.cc
+++ b/test/extensions/common/tap/admin_test.cc
@@ -30,7 +30,9 @@ class AdminHandlerTest : public testing::Test {
     handler_ = std::make_unique<AdminHandler>(admin_, main_thread_dispatcher_);
   }
 
-  ~AdminHandlerTest() { EXPECT_CALL(admin_, removeHandler("/tap")).WillOnce(Return(true)); }
+  ~AdminHandlerTest() override {
+    EXPECT_CALL(admin_, removeHandler("/tap")).WillOnce(Return(true));
+  }
 
   Server::MockAdmin admin_;
   Event::MockDispatcher main_thread_dispatcher_;
diff --git a/test/extensions/common/tap/common.h b/test/extensions/common/tap/common.h
index b98ed66f60b6..dda23a913472 100644
--- a/test/extensions/common/tap/common.h
+++ b/test/extensions/common/tap/common.h
@@ -37,7 +37,7 @@ namespace Tap {
 class MockPerTapSinkHandleManager : public PerTapSinkHandleManager {
 public:
   MockPerTapSinkHandleManager();
-  ~MockPerTapSinkHandleManager();
+  ~MockPerTapSinkHandleManager() override;
 
   void submitTrace(TraceWrapperPtr&& trace) override { submitTrace_(*trace); }
 
@@ -47,7 +47,7 @@ class MockPerTapSinkHandleManager : public PerTapSinkHandleManager {
 class MockMatcher : public Matcher {
 public:
   using Matcher::Matcher;
-  ~MockMatcher();
+  ~MockMatcher() override;
 
   MOCK_CONST_METHOD1(onNewStream, void(MatchStatusVector& statuses));
   MOCK_CONST_METHOD2(onHttpRequestHeaders,
diff --git a/test/extensions/filters/common/ext_authz/mocks.h b/test/extensions/filters/common/ext_authz/mocks.h
index 75ffe3d391c8..8d2dd1a31365 100644
--- a/test/extensions/filters/common/ext_authz/mocks.h
+++ b/test/extensions/filters/common/ext_authz/mocks.h
@@ -16,7 +16,7 @@ namespace ExtAuthz {
 class MockClient : public Client {
 public:
   MockClient();
-  ~MockClient();
+  ~MockClient() override;
 
   // ExtAuthz::Client
   MOCK_METHOD0(cancel, void());
@@ -28,7 +28,7 @@ class MockClient : public Client {
 class MockRequestCallbacks : public RequestCallbacks {
 public:
   MockRequestCallbacks();
-  ~MockRequestCallbacks();
+  ~MockRequestCallbacks() override;
 
   void onComplete(ResponsePtr&& response) override { onComplete_(response); }
 
diff --git a/test/extensions/filters/common/lua/lua_test.cc b/test/extensions/filters/common/lua/lua_test.cc
index b2996f1b92aa..5c430403793a 100644
--- a/test/extensions/filters/common/lua/lua_test.cc
+++ b/test/extensions/filters/common/lua/lua_test.cc
@@ -23,7 +23,7 @@ namespace {
 // not aligned by Envoy. See https://github.com/envoyproxy/envoy/issues/5551 for details.
 class alignas(32) TestObject : public BaseLuaObject<TestObject> {
 public:
-  ~TestObject() { onDestroy(); }
+  ~TestObject() override { onDestroy(); }
 
   static ExportedFunctions exportedFunctions() { return {{"testCall", static_luaTestCall}}; }
 
diff --git a/test/extensions/filters/common/lua/wrappers_test.cc b/test/extensions/filters/common/lua/wrappers_test.cc
index 46428f22aec7..926db9ce3d5e 100644
--- a/test/extensions/filters/common/lua/wrappers_test.cc
+++ b/test/extensions/filters/common/lua/wrappers_test.cc
@@ -18,7 +18,7 @@ class LuaBufferWrapperTest : public LuaWrappersTestBase<BufferWrapper> {};
 
 class LuaMetadataMapWrapperTest : public LuaWrappersTestBase<MetadataMapWrapper> {
 public:
-  virtual void setup(const std::string& script) {
+  void setup(const std::string& script) override {
     LuaWrappersTestBase<MetadataMapWrapper>::setup(script);
     state_->registerType<MetadataMapIterator>();
   }
@@ -32,7 +32,7 @@ class LuaMetadataMapWrapperTest : public LuaWrappersTestBase<MetadataMapWrapper>
 
 class LuaConnectionWrapperTest : public LuaWrappersTestBase<ConnectionWrapper> {
 public:
-  virtual void setup(const std::string& script) {
+  void setup(const std::string& script) override {
     LuaWrappersTestBase<ConnectionWrapper>::setup(script);
     state_->registerType<SslConnectionWrapper>();
   }
diff --git a/test/extensions/filters/common/ratelimit/mocks.h b/test/extensions/filters/common/ratelimit/mocks.h
index accaa311aa4c..4c84e385eef2 100644
--- a/test/extensions/filters/common/ratelimit/mocks.h
+++ b/test/extensions/filters/common/ratelimit/mocks.h
@@ -18,7 +18,7 @@ namespace RateLimit {
 class MockClient : public Client {
 public:
   MockClient();
-  ~MockClient();
+  ~MockClient() override;
 
   // RateLimit::Client
   MOCK_METHOD0(cancel, void());
diff --git a/test/extensions/filters/common/ratelimit/ratelimit_impl_test.cc b/test/extensions/filters/common/ratelimit/ratelimit_impl_test.cc
index 85c704dfa2de..97a5863c0bb6 100644
--- a/test/extensions/filters/common/ratelimit/ratelimit_impl_test.cc
+++ b/test/extensions/filters/common/ratelimit/ratelimit_impl_test.cc
@@ -36,7 +36,7 @@ namespace {
 
 class MockRequestCallbacks : public RequestCallbacks {
 public:
-  void complete(LimitStatus status, Http::HeaderMapPtr&& headers) {
+  void complete(LimitStatus status, Http::HeaderMapPtr&& headers) override {
     complete_(status, headers.get());
   }
 
diff --git a/test/extensions/filters/http/common/aws/credentials_provider_impl_test.cc b/test/extensions/filters/http/common/aws/credentials_provider_impl_test.cc
index d4c22e6215af..b72ea27af87f 100644
--- a/test/extensions/filters/http/common/aws/credentials_provider_impl_test.cc
+++ b/test/extensions/filters/http/common/aws/credentials_provider_impl_test.cc
@@ -20,7 +20,7 @@ namespace Aws {
 
 class EvironmentCredentialsProviderTest : public testing::Test {
 public:
-  ~EvironmentCredentialsProviderTest() {
+  ~EvironmentCredentialsProviderTest() override {
     TestEnvironment::unsetEnvVar("AWS_ACCESS_KEY_ID");
     TestEnvironment::unsetEnvVar("AWS_SECRET_ACCESS_KEY");
     TestEnvironment::unsetEnvVar("AWS_SESSION_TOKEN");
@@ -330,7 +330,7 @@ class DefaultCredentialsProviderChainTest : public testing::Test {
     EXPECT_CALL(factories_, createEnvironmentCredentialsProvider());
   }
 
-  ~DefaultCredentialsProviderChainTest() {
+  ~DefaultCredentialsProviderChainTest() override {
     TestEnvironment::unsetEnvVar("AWS_CONTAINER_CREDENTIALS_RELATIVE_URI");
     TestEnvironment::unsetEnvVar("AWS_CONTAINER_CREDENTIALS_FULL_URI");
     TestEnvironment::unsetEnvVar("AWS_CONTAINER_AUTHORIZATION_TOKEN");
@@ -349,9 +349,9 @@ class DefaultCredentialsProviderChainTest : public testing::Test {
                            Api::Api&,
                            const MetadataCredentialsProviderBase::MetadataFetcher& fetcher));
 
-    virtual CredentialsProviderSharedPtr createTaskRoleCredentialsProvider(
+    CredentialsProviderSharedPtr createTaskRoleCredentialsProvider(
         Api::Api& api, const MetadataCredentialsProviderBase::MetadataFetcher& metadata_fetcher,
-        const std::string& credential_uri, const std::string& authorization_token) const {
+        const std::string& credential_uri, const std::string& authorization_token) const override {
       return createTaskRoleCredentialsProviderMock(api, metadata_fetcher, credential_uri,
                                                    authorization_token);
     }
diff --git a/test/extensions/filters/http/common/aws/mocks.h b/test/extensions/filters/http/common/aws/mocks.h
index 0e4ced802301..df97224efb5e 100644
--- a/test/extensions/filters/http/common/aws/mocks.h
+++ b/test/extensions/filters/http/common/aws/mocks.h
@@ -14,7 +14,7 @@ namespace Aws {
 class MockCredentialsProvider : public CredentialsProvider {
 public:
   MockCredentialsProvider();
-  ~MockCredentialsProvider();
+  ~MockCredentialsProvider() override;
 
   MOCK_METHOD0(getCredentials, Credentials());
 };
@@ -22,7 +22,7 @@ class MockCredentialsProvider : public CredentialsProvider {
 class MockSigner : public Signer {
 public:
   MockSigner();
-  ~MockSigner();
+  ~MockSigner() override;
 
   MOCK_METHOD2(sign, void(Http::Message&, bool));
 };
diff --git a/test/extensions/filters/http/common/aws/region_provider_impl_test.cc b/test/extensions/filters/http/common/aws/region_provider_impl_test.cc
index 42ce4d907bef..7cb14439a521 100644
--- a/test/extensions/filters/http/common/aws/region_provider_impl_test.cc
+++ b/test/extensions/filters/http/common/aws/region_provider_impl_test.cc
@@ -12,7 +12,7 @@ namespace Aws {
 
 class EnvironmentRegionProviderTest : public testing::Test {
 public:
-  virtual ~EnvironmentRegionProviderTest() { TestEnvironment::unsetEnvVar("AWS_REGION"); }
+  ~EnvironmentRegionProviderTest() override { TestEnvironment::unsetEnvVar("AWS_REGION"); }
 
   EnvironmentRegionProvider provider_;
 };
diff --git a/test/extensions/filters/http/common/mock.h b/test/extensions/filters/http/common/mock.h
index 2e16a0c2774f..a60fc266aa06 100644
--- a/test/extensions/filters/http/common/mock.h
+++ b/test/extensions/filters/http/common/mock.h
@@ -46,7 +46,7 @@ class MockJwksReceiver : public JwksFetcher::JwksReceiver {
    * Expectations and assertions should be made on onJwksSuccessImpl in place
    * of onJwksSuccess.
    */
-  void onJwksSuccess(google::jwt_verify::JwksPtr&& jwks) {
+  void onJwksSuccess(google::jwt_verify::JwksPtr&& jwks) override {
     ASSERT(jwks);
     onJwksSuccessImpl(*jwks.get());
   }
diff --git a/test/extensions/filters/http/dynamic_forward_proxy/proxy_filter_test.cc b/test/extensions/filters/http/dynamic_forward_proxy/proxy_filter_test.cc
index 4718dee34720..b741cbc592f3 100644
--- a/test/extensions/filters/http/dynamic_forward_proxy/proxy_filter_test.cc
+++ b/test/extensions/filters/http/dynamic_forward_proxy/proxy_filter_test.cc
@@ -40,7 +40,7 @@ class ProxyFilterTest : public testing::Test,
     cm_.thread_local_cluster_.cluster_.info_->resetResourceManager(0, 1, 0, 0, 0);
   }
 
-  ~ProxyFilterTest() {
+  ~ProxyFilterTest() override {
     EXPECT_TRUE(
         cm_.thread_local_cluster_.cluster_.info_->resource_manager_->pendingRequests().canCreate());
   }
diff --git a/test/extensions/filters/http/dynamo/dynamo_filter_test.cc b/test/extensions/filters/http/dynamo/dynamo_filter_test.cc
index f7021a9b05e9..a21e4734963f 100644
--- a/test/extensions/filters/http/dynamo/dynamo_filter_test.cc
+++ b/test/extensions/filters/http/dynamo/dynamo_filter_test.cc
@@ -41,7 +41,7 @@ class DynamoFilterTest : public testing::Test {
     filter_->setEncoderFilterCallbacks(encoder_callbacks_);
   }
 
-  ~DynamoFilterTest() { filter_->onDestroy(); }
+  ~DynamoFilterTest() override { filter_->onDestroy(); }
 
   std::unique_ptr<DynamoFilter> filter_;
   NiceMock<Runtime::MockLoader> loader_;
diff --git a/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc b/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
index 437bc9d373b4..40181c29e9b7 100644
--- a/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
+++ b/test/extensions/filters/http/grpc_json_transcoder/json_transcoder_filter_test.cc
@@ -740,7 +740,7 @@ class GrpcJsonTranscoderFilterPrintTest
     filter_->setEncoderFilterCallbacks(encoder_callbacks_);
   }
 
-  ~GrpcJsonTranscoderFilterPrintTest() {
+  ~GrpcJsonTranscoderFilterPrintTest() override {
     delete filter_;
     delete config_;
   }
diff --git a/test/extensions/filters/http/ip_tagging/ip_tagging_filter_test.cc b/test/extensions/filters/http/ip_tagging/ip_tagging_filter_test.cc
index 5dfaeaa7cd1b..50679f090c42 100644
--- a/test/extensions/filters/http/ip_tagging/ip_tagging_filter_test.cc
+++ b/test/extensions/filters/http/ip_tagging/ip_tagging_filter_test.cc
@@ -50,7 +50,7 @@ request_type: internal
     filter_->setDecoderFilterCallbacks(filter_callbacks_);
   }
 
-  ~IpTaggingFilterTest() { filter_->onDestroy(); }
+  ~IpTaggingFilterTest() override { filter_->onDestroy(); }
 
   IpTaggingFilterConfigSharedPtr config_;
   std::unique_ptr<IpTaggingFilter> filter_;
diff --git a/test/extensions/filters/http/jwt_authn/filter_integration_test.cc b/test/extensions/filters/http/jwt_authn/filter_integration_test.cc
index f65637c7fcfb..7f064293f3e2 100644
--- a/test/extensions/filters/http/jwt_authn/filter_integration_test.cc
+++ b/test/extensions/filters/http/jwt_authn/filter_integration_test.cc
@@ -47,7 +47,8 @@ class HeaderToFilterStateFilterConfig : public Common::EmptyHttpFilterConfig {
   HeaderToFilterStateFilterConfig()
       : Common::EmptyHttpFilterConfig(HeaderToFilterStateFilterName) {}
 
-  Http::FilterFactoryCb createFilter(const std::string&, Server::Configuration::FactoryContext&) {
+  Http::FilterFactoryCb createFilter(const std::string&,
+                                     Server::Configuration::FactoryContext&) override {
     return [](Http::FilterChainFactoryCallbacks& callbacks) -> void {
       callbacks.addStreamDecoderFilter(
           std::make_shared<HeaderToFilterStateFilter>("jwt_selector", "jwt_selector"));
diff --git a/test/extensions/filters/http/jwt_authn/mock.h b/test/extensions/filters/http/jwt_authn/mock.h
index a97342ae11b4..025351a35dc0 100644
--- a/test/extensions/filters/http/jwt_authn/mock.h
+++ b/test/extensions/filters/http/jwt_authn/mock.h
@@ -28,7 +28,7 @@ class MockAuthenticator : public Authenticator {
                               SetPayloadCallback set_payload_cb, AuthenticatorCallback callback));
 
   void verify(Http::HeaderMap& headers, std::vector<JwtLocationConstPtr>&& tokens,
-              SetPayloadCallback set_payload_cb, AuthenticatorCallback callback) {
+              SetPayloadCallback set_payload_cb, AuthenticatorCallback callback) override {
     doVerify(headers, &tokens, std::move(set_payload_cb), std::move(callback));
   }
 
diff --git a/test/extensions/filters/http/lua/lua_filter_test.cc b/test/extensions/filters/http/lua/lua_filter_test.cc
index d9be20d3f301..2d444fc6f61a 100644
--- a/test/extensions/filters/http/lua/lua_filter_test.cc
+++ b/test/extensions/filters/http/lua/lua_filter_test.cc
@@ -66,7 +66,7 @@ class LuaHttpFilterTest : public testing::Test {
     EXPECT_CALL(encoder_callbacks_, encodingBuffer()).Times(AtLeast(0));
   }
 
-  ~LuaHttpFilterTest() { filter_->onDestroy(); }
+  ~LuaHttpFilterTest() override { filter_->onDestroy(); }
 
   void setup(const std::string& lua_code) {
     config_.reset(new FilterConfig(lua_code, tls_, cluster_manager_));
diff --git a/test/extensions/filters/http/rbac/rbac_filter_test.cc b/test/extensions/filters/http/rbac/rbac_filter_test.cc
index 62967602dfc6..ecc0b1dcafac 100644
--- a/test/extensions/filters/http/rbac/rbac_filter_test.cc
+++ b/test/extensions/filters/http/rbac/rbac_filter_test.cc
@@ -47,7 +47,7 @@ class RoleBasedAccessControlFilterTest : public testing::Test {
 
   RoleBasedAccessControlFilterTest() : config_(setupConfig()), filter_(config_) {}
 
-  void SetUp() {
+  void SetUp() override {
     EXPECT_CALL(callbacks_, connection()).WillRepeatedly(Return(&connection_));
     EXPECT_CALL(callbacks_, streamInfo()).WillRepeatedly(ReturnRef(req_info_));
     filter_.setDecoderFilterCallbacks(callbacks_);
diff --git a/test/extensions/filters/listener/http_inspector/http_inspector_test.cc b/test/extensions/filters/listener/http_inspector/http_inspector_test.cc
index f1aa3012c7bf..e5cb254902c8 100644
--- a/test/extensions/filters/listener/http_inspector/http_inspector_test.cc
+++ b/test/extensions/filters/listener/http_inspector/http_inspector_test.cc
@@ -33,7 +33,7 @@ class HttpInspectorTest : public testing::Test {
   HttpInspectorTest()
       : cfg_(std::make_shared<Config>(store_)),
         io_handle_(std::make_unique<Network::IoSocketHandleImpl>(42)) {}
-  ~HttpInspectorTest() { io_handle_->close(); }
+  ~HttpInspectorTest() override { io_handle_->close(); }
 
   void init() {
     filter_ = std::make_unique<Filter>(cfg_);
diff --git a/test/extensions/filters/listener/tls_inspector/tls_inspector_test.cc b/test/extensions/filters/listener/tls_inspector/tls_inspector_test.cc
index 9412e3a0caf6..63cff699cffe 100644
--- a/test/extensions/filters/listener/tls_inspector/tls_inspector_test.cc
+++ b/test/extensions/filters/listener/tls_inspector/tls_inspector_test.cc
@@ -34,7 +34,7 @@ class TlsInspectorTest : public testing::Test {
   TlsInspectorTest()
       : cfg_(std::make_shared<Config>(store_)),
         io_handle_(std::make_unique<Network::IoSocketHandleImpl>(42)) {}
-  ~TlsInspectorTest() { io_handle_->close(); }
+  ~TlsInspectorTest() override { io_handle_->close(); }
 
   void init() {
     filter_ = std::make_unique<Filter>(cfg_);
diff --git a/test/extensions/filters/network/client_ssl_auth/client_ssl_auth_test.cc b/test/extensions/filters/network/client_ssl_auth/client_ssl_auth_test.cc
index 7c5e09642488..5321d370a189 100644
--- a/test/extensions/filters/network/client_ssl_auth/client_ssl_auth_test.cc
+++ b/test/extensions/filters/network/client_ssl_auth/client_ssl_auth_test.cc
@@ -59,7 +59,7 @@ class ClientSslAuthFilterTest : public testing::Test {
   ClientSslAuthFilterTest()
       : request_(&cm_.async_client_), interval_timer_(new Event::MockTimer(&dispatcher_)),
         api_(Api::createApiForTest(stats_store_)) {}
-  ~ClientSslAuthFilterTest() { tls_.shutdownThread(); }
+  ~ClientSslAuthFilterTest() override { tls_.shutdownThread(); }
 
   void setup() {
     std::string yaml = R"EOF(
diff --git a/test/extensions/filters/network/common/redis/client_impl_test.cc b/test/extensions/filters/network/common/redis/client_impl_test.cc
index ecea5c887c22..fd7d9ec9b7e5 100644
--- a/test/extensions/filters/network/common/redis/client_impl_test.cc
+++ b/test/extensions/filters/network/common/redis/client_impl_test.cc
@@ -43,7 +43,7 @@ class RedisClientImplTest : public testing::Test, public Common::Redis::DecoderF
     return Common::Redis::DecoderPtr{decoder_};
   }
 
-  ~RedisClientImplTest() {
+  ~RedisClientImplTest() override {
     client_.reset();
 
     EXPECT_TRUE(TestUtility::gaugesZeroed(host_->cluster_.stats_store_.gauges()));
diff --git a/test/extensions/filters/network/common/redis/mocks.h b/test/extensions/filters/network/common/redis/mocks.h
index 829983abd53d..859ea03cf42b 100644
--- a/test/extensions/filters/network/common/redis/mocks.h
+++ b/test/extensions/filters/network/common/redis/mocks.h
@@ -27,7 +27,7 @@ void PrintTo(const RespValuePtr& value, std::ostream* os);
 class MockEncoder : public Common::Redis::Encoder {
 public:
   MockEncoder();
-  ~MockEncoder();
+  ~MockEncoder() override;
 
   MOCK_METHOD2(encode, void(const Common::Redis::RespValue& value, Buffer::Instance& out));
 
@@ -38,7 +38,7 @@ class MockEncoder : public Common::Redis::Encoder {
 class MockDecoder : public Common::Redis::Decoder {
 public:
   MockDecoder();
-  ~MockDecoder();
+  ~MockDecoder() override;
 
   MOCK_METHOD1(decode, void(Buffer::Instance& data));
 };
@@ -48,7 +48,7 @@ namespace Client {
 class MockClient : public Client {
 public:
   MockClient();
-  ~MockClient();
+  ~MockClient() override;
 
   void raiseEvent(Network::ConnectionEvent event) {
     for (Network::ConnectionCallbacks* callbacks : callbacks_) {
@@ -80,7 +80,7 @@ class MockClient : public Client {
 class MockPoolRequest : public PoolRequest {
 public:
   MockPoolRequest();
-  ~MockPoolRequest();
+  ~MockPoolRequest() override;
 
   MOCK_METHOD0(cancel, void());
 };
@@ -88,7 +88,7 @@ class MockPoolRequest : public PoolRequest {
 class MockPoolCallbacks : public PoolCallbacks {
 public:
   MockPoolCallbacks();
-  ~MockPoolCallbacks();
+  ~MockPoolCallbacks() override;
 
   void onResponse(Common::Redis::RespValuePtr&& value) override { onResponse_(value); }
 
diff --git a/test/extensions/filters/network/dubbo_proxy/conn_manager_test.cc b/test/extensions/filters/network/dubbo_proxy/conn_manager_test.cc
index f099e1dae233..a8dc3e35d24c 100644
--- a/test/extensions/filters/network/dubbo_proxy/conn_manager_test.cc
+++ b/test/extensions/filters/network/dubbo_proxy/conn_manager_test.cc
@@ -89,7 +89,9 @@ class TestConfigImpl : public ConfigImpl {
 class ConnectionManagerTest : public testing::Test {
 public:
   ConnectionManagerTest() : stats_(DubboFilterStats::generateStats("test.", store_)) {}
-  ~ConnectionManagerTest() { filter_callbacks_.connection_.dispatcher_.clearDeferredDeleteList(); }
+  ~ConnectionManagerTest() override {
+    filter_callbacks_.connection_.dispatcher_.clearDeferredDeleteList();
+  }
 
   TimeSource& timeSystem() { return factory_context_.dispatcher().timeSource(); }
 
diff --git a/test/extensions/filters/network/dubbo_proxy/decoder_test.cc b/test/extensions/filters/network/dubbo_proxy/decoder_test.cc
index ae9c291011c2..aade1c594766 100644
--- a/test/extensions/filters/network/dubbo_proxy/decoder_test.cc
+++ b/test/extensions/filters/network/dubbo_proxy/decoder_test.cc
@@ -60,7 +60,7 @@ class DubboDecoderStateMachineTest : public DecoderStateMachineTestBase, public
 class DubboDecoderTest : public testing::Test {
 public:
   DubboDecoderTest() = default;
-  virtual ~DubboDecoderTest() override = default;
+  ~DubboDecoderTest() override = default;
 
   NiceMock<MockProtocol> protocol_;
   NiceMock<MockStreamHandler> handler_;
diff --git a/test/extensions/filters/network/dubbo_proxy/mocks.h b/test/extensions/filters/network/dubbo_proxy/mocks.h
index 884ab0f821ee..02a5176f1485 100644
--- a/test/extensions/filters/network/dubbo_proxy/mocks.h
+++ b/test/extensions/filters/network/dubbo_proxy/mocks.h
@@ -47,7 +47,7 @@ class MockStreamHandler : public StreamHandler {
 class MockRequestDecoderCallbacks : public RequestDecoderCallbacks {
 public:
   MockRequestDecoderCallbacks();
-  ~MockRequestDecoderCallbacks() = default;
+  ~MockRequestDecoderCallbacks() override = default;
 
   MOCK_METHOD0(newStream, StreamHandler&());
   MOCK_METHOD1(onHeartbeat, void(MessageMetadataSharedPtr));
@@ -57,7 +57,7 @@ class MockRequestDecoderCallbacks : public RequestDecoderCallbacks {
 class MockResponseDecoderCallbacks : public ResponseDecoderCallbacks {
 public:
   MockResponseDecoderCallbacks();
-  ~MockResponseDecoderCallbacks() = default;
+  ~MockResponseDecoderCallbacks() override = default;
 
   MOCK_METHOD0(newStream, StreamHandler&());
   MOCK_METHOD1(onHeartbeat, void(MessageMetadataSharedPtr));
@@ -79,7 +79,7 @@ class MockActiveStream : public ActiveStream {
 class MockDecoderStateMachineDelegate : public DecoderStateMachine::Delegate {
 public:
   MockDecoderStateMachineDelegate() = default;
-  ~MockDecoderStateMachineDelegate() = default;
+  ~MockDecoderStateMachineDelegate() override = default;
 
   MOCK_METHOD2(newStream, ActiveStream*(MessageMetadataSharedPtr, ContextSharedPtr));
   MOCK_METHOD1(onHeartbeat, void(MessageMetadataSharedPtr));
@@ -88,7 +88,7 @@ class MockDecoderStateMachineDelegate : public DecoderStateMachine::Delegate {
 class MockSerializer : public Serializer {
 public:
   MockSerializer();
-  ~MockSerializer();
+  ~MockSerializer() override;
 
   // DubboProxy::Serializer
   MOCK_CONST_METHOD0(name, const std::string&());
@@ -106,7 +106,7 @@ class MockSerializer : public Serializer {
 class MockProtocol : public Protocol {
 public:
   MockProtocol();
-  ~MockProtocol();
+  ~MockProtocol() override;
 
   MOCK_CONST_METHOD0(name, const std::string&());
   MOCK_CONST_METHOD0(type, ProtocolType());
@@ -157,7 +157,7 @@ namespace DubboFilters {
 class MockFilterChainFactoryCallbacks : public FilterChainFactoryCallbacks {
 public:
   MockFilterChainFactoryCallbacks();
-  ~MockFilterChainFactoryCallbacks();
+  ~MockFilterChainFactoryCallbacks() override;
 
   MOCK_METHOD1(addDecoderFilter, void(DecoderFilterSharedPtr));
   MOCK_METHOD1(addEncoderFilter, void(EncoderFilterSharedPtr));
@@ -167,7 +167,7 @@ class MockFilterChainFactoryCallbacks : public FilterChainFactoryCallbacks {
 class MockDecoderFilter : public DecoderFilter {
 public:
   MockDecoderFilter();
-  ~MockDecoderFilter();
+  ~MockDecoderFilter() override;
 
   // DubboProxy::DubboFilters::DecoderFilter
   MOCK_METHOD0(onDestroy, void());
@@ -178,7 +178,7 @@ class MockDecoderFilter : public DecoderFilter {
 class MockDecoderFilterCallbacks : public DecoderFilterCallbacks {
 public:
   MockDecoderFilterCallbacks();
-  ~MockDecoderFilterCallbacks();
+  ~MockDecoderFilterCallbacks() override;
 
   // DubboProxy::DubboFilters::DecoderFilterCallbacks
   MOCK_CONST_METHOD0(requestId, uint64_t());
@@ -206,7 +206,7 @@ class MockDecoderFilterCallbacks : public DecoderFilterCallbacks {
 class MockEncoderFilter : public EncoderFilter {
 public:
   MockEncoderFilter();
-  ~MockEncoderFilter();
+  ~MockEncoderFilter() override;
 
   // DubboProxy::DubboFilters::EncoderFilter
   MOCK_METHOD0(onDestroy, void());
@@ -217,7 +217,7 @@ class MockEncoderFilter : public EncoderFilter {
 class MockEncoderFilterCallbacks : public EncoderFilterCallbacks {
 public:
   MockEncoderFilterCallbacks();
-  ~MockEncoderFilterCallbacks();
+  ~MockEncoderFilterCallbacks() override;
 
   // DubboProxy::DubboFilters::MockEncoderFilterCallbacks
   MOCK_CONST_METHOD0(requestId, uint64_t());
@@ -242,7 +242,7 @@ class MockEncoderFilterCallbacks : public EncoderFilterCallbacks {
 class MockCodecFilter : public CodecFilter {
 public:
   MockCodecFilter();
-  ~MockCodecFilter();
+  ~MockCodecFilter() override;
 
   MOCK_METHOD0(onDestroy, void());
   MOCK_METHOD1(setEncoderFilterCallbacks, void(EncoderFilterCallbacks& callbacks));
@@ -254,7 +254,7 @@ class MockCodecFilter : public CodecFilter {
 class MockDirectResponse : public DirectResponse {
 public:
   MockDirectResponse() = default;
-  ~MockDirectResponse() = default;
+  ~MockDirectResponse() override = default;
 
   MOCK_CONST_METHOD3(encode,
                      DirectResponse::ResponseType(MessageMetadata&, Protocol&, Buffer::Instance&));
@@ -291,7 +291,7 @@ template <class ConfigProto> class MockFactoryBase : public NamedDubboFilterConf
 class MockFilterConfigFactory : public MockFactoryBase<ProtobufWkt::Struct> {
 public:
   MockFilterConfigFactory();
-  ~MockFilterConfigFactory();
+  ~MockFilterConfigFactory() override;
 
   DubboFilters::FilterFactoryCb
   createFilterFactoryFromProtoTyped(const ProtobufWkt::Struct& proto_config,
@@ -310,7 +310,7 @@ namespace Router {
 class MockRouteEntry : public RouteEntry {
 public:
   MockRouteEntry();
-  ~MockRouteEntry();
+  ~MockRouteEntry() override;
 
   // DubboProxy::Router::RouteEntry
   MOCK_CONST_METHOD0(clusterName, const std::string&());
@@ -322,7 +322,7 @@ class MockRouteEntry : public RouteEntry {
 class MockRoute : public Route {
 public:
   MockRoute();
-  ~MockRoute();
+  ~MockRoute() override;
 
   // DubboProxy::Router::Route
   MOCK_CONST_METHOD0(routeEntry, const RouteEntry*());
diff --git a/test/extensions/filters/network/ext_authz/ext_authz_test.cc b/test/extensions/filters/network/ext_authz/ext_authz_test.cc
index 1e4d08186dce..8a344ed162f5 100644
--- a/test/extensions/filters/network/ext_authz/ext_authz_test.cc
+++ b/test/extensions/filters/network/ext_authz/ext_authz_test.cc
@@ -69,7 +69,7 @@ class ExtAuthzFilterTest : public testing::Test {
     return response;
   }
 
-  ~ExtAuthzFilterTest() {
+  ~ExtAuthzFilterTest() override {
     for (const Stats::GaugeSharedPtr& gauge : stats_store_.gauges()) {
       EXPECT_EQ(0U, gauge->value());
     }
diff --git a/test/extensions/filters/network/kafka/serialization_utilities.h b/test/extensions/filters/network/kafka/serialization_utilities.h
index caadecb8b69d..8417afb6e61e 100644
--- a/test/extensions/filters/network/kafka/serialization_utilities.h
+++ b/test/extensions/filters/network/kafka/serialization_utilities.h
@@ -120,16 +120,14 @@ template <typename Base, typename Message, typename Failure> class CapturingCall
   /**
    * Stores the message.
    */
-  virtual void onMessage(Message message) override { captured_messages_.push_back(message); }
+  void onMessage(Message message) override { captured_messages_.push_back(message); }
 
   /**
    * Returns the stored messages.
    */
   const std::vector<Message>& getCapturedMessages() const { return captured_messages_; }
 
-  virtual void onFailedParse(Failure failure_data) override {
-    parse_failures_.push_back(failure_data);
-  }
+  void onFailedParse(Failure failure_data) override { parse_failures_.push_back(failure_data); }
 
   const std::vector<Failure>& getParseFailures() const { return parse_failures_; }
 
diff --git a/test/extensions/filters/network/ratelimit/ratelimit_test.cc b/test/extensions/filters/network/ratelimit/ratelimit_test.cc
index 1ff47f4dbe6c..0b639e1275d2 100644
--- a/test/extensions/filters/network/ratelimit/ratelimit_test.cc
+++ b/test/extensions/filters/network/ratelimit/ratelimit_test.cc
@@ -50,7 +50,7 @@ class RateLimitFilterTest : public testing::Test {
     filter_->onBelowWriteBufferLowWatermark();
   }
 
-  ~RateLimitFilterTest() {
+  ~RateLimitFilterTest() override {
     for (const Stats::GaugeSharedPtr& gauge : stats_store_.gauges()) {
       EXPECT_EQ(0U, gauge->value());
     }
diff --git a/test/extensions/filters/network/redis_proxy/command_lookup_speed_test.cc b/test/extensions/filters/network/redis_proxy/command_lookup_speed_test.cc
index b4be8f79419f..173e5efc8c2a 100644
--- a/test/extensions/filters/network/redis_proxy/command_lookup_speed_test.cc
+++ b/test/extensions/filters/network/redis_proxy/command_lookup_speed_test.cc
@@ -24,7 +24,7 @@ namespace RedisProxy {
 class NoOpSplitCallbacks : public CommandSplitter::SplitCallbacks {
 public:
   NoOpSplitCallbacks() = default;
-  ~NoOpSplitCallbacks() = default;
+  ~NoOpSplitCallbacks() override = default;
 
   bool connectionAllowed() override { return true; }
   void onAuth(const std::string&) override {}
diff --git a/test/extensions/filters/network/redis_proxy/mocks.h b/test/extensions/filters/network/redis_proxy/mocks.h
index cafd3f31966d..7a169df1f767 100644
--- a/test/extensions/filters/network/redis_proxy/mocks.h
+++ b/test/extensions/filters/network/redis_proxy/mocks.h
@@ -22,7 +22,7 @@ namespace RedisProxy {
 class MockRouter : public Router {
 public:
   MockRouter();
-  ~MockRouter();
+  ~MockRouter() override;
 
   MOCK_METHOD1(upstreamPool, RouteSharedPtr(std::string& key));
 };
@@ -30,7 +30,7 @@ class MockRouter : public Router {
 class MockRoute : public Route {
 public:
   MockRoute(ConnPool::InstanceSharedPtr);
-  ~MockRoute();
+  ~MockRoute() override;
 
   MOCK_CONST_METHOD0(upstream, ConnPool::InstanceSharedPtr());
   MOCK_CONST_METHOD0(mirrorPolicies, const MirrorPolicies&());
@@ -45,7 +45,7 @@ namespace ConnPool {
 class MockInstance : public Instance {
 public:
   MockInstance();
-  ~MockInstance();
+  ~MockInstance() override;
 
   MOCK_METHOD3(makeRequest,
                Common::Redis::Client::PoolRequest*(
@@ -64,7 +64,7 @@ namespace CommandSplitter {
 class MockSplitRequest : public SplitRequest {
 public:
   MockSplitRequest();
-  ~MockSplitRequest();
+  ~MockSplitRequest() override;
 
   MOCK_METHOD0(cancel, void());
 };
@@ -72,7 +72,7 @@ class MockSplitRequest : public SplitRequest {
 class MockSplitCallbacks : public SplitCallbacks {
 public:
   MockSplitCallbacks();
-  ~MockSplitCallbacks();
+  ~MockSplitCallbacks() override;
 
   MOCK_METHOD0(connectionAllowed, bool());
   MOCK_METHOD1(onAuth, void(const std::string& password));
@@ -85,7 +85,7 @@ class MockSplitCallbacks : public SplitCallbacks {
 class MockInstance : public Instance {
 public:
   MockInstance();
-  ~MockInstance();
+  ~MockInstance() override;
 
   SplitRequestPtr makeRequest(Common::Redis::RespValuePtr&& request,
                               SplitCallbacks& callbacks) override {
diff --git a/test/extensions/filters/network/thrift_proxy/header_transport_impl_test.cc b/test/extensions/filters/network/thrift_proxy/header_transport_impl_test.cc
index c29cf0a02220..791a2f9f4d59 100644
--- a/test/extensions/filters/network/thrift_proxy/header_transport_impl_test.cc
+++ b/test/extensions/filters/network/thrift_proxy/header_transport_impl_test.cc
@@ -25,7 +25,7 @@ namespace {
 class MockBuffer : public Envoy::MockBuffer {
 public:
   MockBuffer() = default;
-  ~MockBuffer() = default;
+  ~MockBuffer() override = default;
 
   MOCK_CONST_METHOD0(length, uint64_t());
 };
diff --git a/test/extensions/filters/network/thrift_proxy/mocks.h b/test/extensions/filters/network/thrift_proxy/mocks.h
index 1d4f8631eba1..542cbca2f170 100644
--- a/test/extensions/filters/network/thrift_proxy/mocks.h
+++ b/test/extensions/filters/network/thrift_proxy/mocks.h
@@ -28,7 +28,7 @@ namespace ThriftProxy {
 class MockConfig : public Config {
 public:
   MockConfig();
-  ~MockConfig();
+  ~MockConfig() override;
 
   // ThriftProxy::Config
   MOCK_METHOD0(filterFactory, ThriftFilters::FilterChainFactory&());
@@ -40,7 +40,7 @@ class MockConfig : public Config {
 class MockTransport : public Transport {
 public:
   MockTransport();
-  ~MockTransport();
+  ~MockTransport() override;
 
   // ThriftProxy::Transport
   MOCK_CONST_METHOD0(name, const std::string&());
@@ -56,7 +56,7 @@ class MockTransport : public Transport {
 class MockProtocol : public Protocol {
 public:
   MockProtocol();
-  ~MockProtocol();
+  ~MockProtocol() override;
 
   // ThriftProxy::Protocol
   MOCK_CONST_METHOD0(name, const std::string&());
@@ -121,7 +121,7 @@ class MockProtocol : public Protocol {
 class MockDecoderCallbacks : public DecoderCallbacks {
 public:
   MockDecoderCallbacks();
-  ~MockDecoderCallbacks();
+  ~MockDecoderCallbacks() override;
 
   // ThriftProxy::DecoderCallbacks
   MOCK_METHOD0(newDecoderEventHandler, DecoderEventHandler&());
@@ -130,7 +130,7 @@ class MockDecoderCallbacks : public DecoderCallbacks {
 class MockDecoderEventHandler : public DecoderEventHandler {
 public:
   MockDecoderEventHandler();
-  ~MockDecoderEventHandler();
+  ~MockDecoderEventHandler() override;
 
   // ThriftProxy::DecoderEventHandler
   MOCK_METHOD1(transportBegin, FilterStatus(MessageMetadataSharedPtr metadata));
@@ -160,7 +160,7 @@ class MockDecoderEventHandler : public DecoderEventHandler {
 class MockDirectResponse : public DirectResponse {
 public:
   MockDirectResponse();
-  ~MockDirectResponse();
+  ~MockDirectResponse() override;
 
   // ThriftProxy::DirectResponse
   MOCK_CONST_METHOD3(encode,
@@ -170,7 +170,7 @@ class MockDirectResponse : public DirectResponse {
 class MockThriftObject : public ThriftObject {
 public:
   MockThriftObject();
-  ~MockThriftObject();
+  ~MockThriftObject() override;
 
   MOCK_CONST_METHOD0(fields, ThriftFieldPtrList&());
   MOCK_METHOD1(onData, bool(Buffer::Instance&));
@@ -185,7 +185,7 @@ namespace ThriftFilters {
 class MockFilterChainFactoryCallbacks : public FilterChainFactoryCallbacks {
 public:
   MockFilterChainFactoryCallbacks();
-  ~MockFilterChainFactoryCallbacks();
+  ~MockFilterChainFactoryCallbacks() override;
 
   MOCK_METHOD1(addDecoderFilter, void(DecoderFilterSharedPtr));
 };
@@ -193,7 +193,7 @@ class MockFilterChainFactoryCallbacks : public FilterChainFactoryCallbacks {
 class MockDecoderFilter : public DecoderFilter {
 public:
   MockDecoderFilter();
-  ~MockDecoderFilter();
+  ~MockDecoderFilter() override;
 
   // ThriftProxy::ThriftFilters::DecoderFilter
   MOCK_METHOD0(onDestroy, void());
@@ -228,7 +228,7 @@ class MockDecoderFilter : public DecoderFilter {
 class MockDecoderFilterCallbacks : public DecoderFilterCallbacks {
 public:
   MockDecoderFilterCallbacks();
-  ~MockDecoderFilterCallbacks();
+  ~MockDecoderFilterCallbacks() override;
 
   // ThriftProxy::ThriftFilters::DecoderFilterCallbacks
   MOCK_CONST_METHOD0(streamId, uint64_t());
@@ -252,7 +252,7 @@ class MockDecoderFilterCallbacks : public DecoderFilterCallbacks {
 class MockFilterConfigFactory : public ThriftFilters::FactoryBase<ProtobufWkt::Struct> {
 public:
   MockFilterConfigFactory();
-  ~MockFilterConfigFactory();
+  ~MockFilterConfigFactory() override;
 
   ThriftFilters::FilterFactoryCb
   createFilterFactoryFromProtoTyped(const ProtobufWkt::Struct& proto_config,
@@ -271,7 +271,7 @@ namespace Router {
 class MockRateLimitPolicyEntry : public RateLimitPolicyEntry {
 public:
   MockRateLimitPolicyEntry();
-  ~MockRateLimitPolicyEntry();
+  ~MockRateLimitPolicyEntry() override;
 
   MOCK_CONST_METHOD0(stage, uint32_t());
   MOCK_CONST_METHOD0(disableKey, const std::string&());
@@ -286,7 +286,7 @@ class MockRateLimitPolicyEntry : public RateLimitPolicyEntry {
 class MockRateLimitPolicy : public RateLimitPolicy {
 public:
   MockRateLimitPolicy();
-  ~MockRateLimitPolicy();
+  ~MockRateLimitPolicy() override;
 
   MOCK_CONST_METHOD0(empty, bool());
   MOCK_CONST_METHOD1(
@@ -299,7 +299,7 @@ class MockRateLimitPolicy : public RateLimitPolicy {
 class MockRouteEntry : public RouteEntry {
 public:
   MockRouteEntry();
-  ~MockRouteEntry();
+  ~MockRouteEntry() override;
 
   // ThriftProxy::Router::RouteEntry
   MOCK_CONST_METHOD0(clusterName, const std::string&());
@@ -313,7 +313,7 @@ class MockRouteEntry : public RouteEntry {
 class MockRoute : public Route {
 public:
   MockRoute();
-  ~MockRoute();
+  ~MockRoute() override;
 
   // ThriftProxy::Router::Route
   MOCK_CONST_METHOD0(routeEntry, const RouteEntry*());
diff --git a/test/extensions/grpc_credentials/file_based_metadata/file_based_metadata_grpc_credentials_test.cc b/test/extensions/grpc_credentials/file_based_metadata/file_based_metadata_grpc_credentials_test.cc
index ec1f153c8d4f..d683abfa4974 100644
--- a/test/extensions/grpc_credentials/file_based_metadata/file_based_metadata_grpc_credentials_test.cc
+++ b/test/extensions/grpc_credentials/file_based_metadata/file_based_metadata_grpc_credentials_test.cc
@@ -30,7 +30,7 @@ class GrpcFileBasedMetadataClientIntegrationTest : public GrpcSslClientIntegrati
     }
   }
 
-  virtual envoy::api::v2::core::GrpcService createGoogleGrpcConfig() override {
+  envoy::api::v2::core::GrpcService createGoogleGrpcConfig() override {
     auto config = GrpcClientIntegrationTest::createGoogleGrpcConfig();
     auto* google_grpc = config.mutable_google_grpc();
     google_grpc->set_credentials_factory_name(credentials_factory_name_);
diff --git a/test/extensions/quic_listeners/quiche/platform/quic_mock_log_impl.h b/test/extensions/quic_listeners/quiche/platform/quic_mock_log_impl.h
index b57b9fe48ffc..ea9326cc4eb2 100644
--- a/test/extensions/quic_listeners/quiche/platform/quic_mock_log_impl.h
+++ b/test/extensions/quic_listeners/quiche/platform/quic_mock_log_impl.h
@@ -21,7 +21,7 @@ class QuicEnvoyMockLog : public QuicLogSink {
 public:
   QuicEnvoyMockLog() : is_capturing_(false) {}
 
-  virtual ~QuicEnvoyMockLog() {
+  ~QuicEnvoyMockLog() override {
     if (is_capturing_) {
       StopCapturingLogs();
     }
diff --git a/test/extensions/quic_listeners/quiche/platform/quic_platform_test.cc b/test/extensions/quic_listeners/quiche/platform/quic_platform_test.cc
index 34e406378117..090d948bfa6f 100644
--- a/test/extensions/quic_listeners/quiche/platform/quic_platform_test.cc
+++ b/test/extensions/quic_listeners/quiche/platform/quic_platform_test.cc
@@ -85,7 +85,7 @@ class QuicPlatformTest : public testing::Test {
     GetLogger().set_level(ERROR);
   }
 
-  ~QuicPlatformTest() {
+  ~QuicPlatformTest() override {
     SetVerbosityLogThreshold(verbosity_log_threshold_);
     GetLogger().set_level(log_level_);
   }
diff --git a/test/extensions/stats_sinks/metrics_service/grpc_metrics_service_impl_test.cc b/test/extensions/stats_sinks/metrics_service/grpc_metrics_service_impl_test.cc
index 30fabc69b5f2..4ed180c0a05f 100644
--- a/test/extensions/stats_sinks/metrics_service/grpc_metrics_service_impl_test.cc
+++ b/test/extensions/stats_sinks/metrics_service/grpc_metrics_service_impl_test.cc
@@ -91,7 +91,7 @@ class TestGrpcMetricsStreamer : public GrpcMetricsStreamer {
 public:
   int metric_count;
   // GrpcMetricsStreamer
-  void send(envoy::service::metrics::v2::StreamMetricsMessage& message) {
+  void send(envoy::service::metrics::v2::StreamMetricsMessage& message) override {
     metric_count = message.envoy_metrics_size();
   }
 };
diff --git a/test/extensions/tracers/zipkin/tracer_test.cc b/test/extensions/tracers/zipkin/tracer_test.cc
index 0b1de42b7221..04fdbe3e07b4 100644
--- a/test/extensions/tracers/zipkin/tracer_test.cc
+++ b/test/extensions/tracers/zipkin/tracer_test.cc
@@ -28,7 +28,7 @@ namespace {
 class TestReporterImpl : public Reporter {
 public:
   TestReporterImpl(int value) : value_(value) {}
-  void reportSpan(const Span& span) { reported_spans_.push_back(span); }
+  void reportSpan(const Span& span) override { reported_spans_.push_back(span); }
   int getValue() { return value_; }
   std::vector<Span>& reportedSpans() { return reported_spans_; }
 
diff --git a/test/integration/autonomous_upstream.h b/test/integration/autonomous_upstream.h
index bdfc8a8eaa73..e749294d7426 100644
--- a/test/integration/autonomous_upstream.h
+++ b/test/integration/autonomous_upstream.h
@@ -22,7 +22,7 @@ class AutonomousStream : public FakeStream {
 
   AutonomousStream(FakeHttpConnection& parent, Http::StreamEncoder& encoder,
                    AutonomousUpstream& upstream);
-  ~AutonomousStream();
+  ~AutonomousStream() override;
 
   void setEndStream(bool set) override;
 
@@ -55,7 +55,7 @@ class AutonomousUpstream : public FakeUpstream {
   AutonomousUpstream(uint32_t port, FakeHttpConnection::Type type,
                      Network::Address::IpVersion version, Event::TestTimeSystem& time_system)
       : FakeUpstream(port, type, version, time_system) {}
-  ~AutonomousUpstream();
+  ~AutonomousUpstream() override;
   bool
   createNetworkFilterChain(Network::Connection& connection,
                            const std::vector<Network::FilterFactoryCb>& filter_factories) override;
diff --git a/test/integration/fake_upstream.h b/test/integration/fake_upstream.h
index 72b831ad4664..4338e4a1e998 100644
--- a/test/integration/fake_upstream.h
+++ b/test/integration/fake_upstream.h
@@ -531,7 +531,7 @@ class FakeUpstream : Logger::Loggable<Logger::Id::testing>,
   FakeUpstream(Network::TransportSocketFactoryPtr&& transport_socket_factory, uint32_t port,
                FakeHttpConnection::Type type, Network::Address::IpVersion version,
                Event::TestTimeSystem& time_system);
-  ~FakeUpstream();
+  ~FakeUpstream() override;
 
   FakeHttpConnection::Type httpType() { return http_type_; }
 
diff --git a/test/integration/filters/add_trailers_filter.cc b/test/integration/filters/add_trailers_filter.cc
index dd6c0f0fa0d2..cd698d71e736 100644
--- a/test/integration/filters/add_trailers_filter.cc
+++ b/test/integration/filters/add_trailers_filter.cc
@@ -12,7 +12,7 @@ namespace Envoy {
 // A test filter that inserts trailers at the end of encode/decode
 class AddTrailersStreamFilter : public Http::PassThroughFilter {
 public:
-  Http::FilterDataStatus decodeData(Buffer::Instance&, bool end_stream) {
+  Http::FilterDataStatus decodeData(Buffer::Instance&, bool end_stream) override {
     if (end_stream) {
       decoder_callbacks_->addDecodedTrailers().insertGrpcMessage().value(std::string("decode"));
     }
@@ -20,7 +20,7 @@ class AddTrailersStreamFilter : public Http::PassThroughFilter {
     return Http::FilterDataStatus::Continue;
   }
 
-  Http::FilterDataStatus encodeData(Buffer::Instance&, bool end_stream) {
+  Http::FilterDataStatus encodeData(Buffer::Instance&, bool end_stream) override {
     if (end_stream) {
       encoder_callbacks_->addEncodedTrailers().insertGrpcMessage().value(std::string("encode"));
     }
@@ -34,7 +34,8 @@ class AddTrailersStreamFilterConfig
 public:
   AddTrailersStreamFilterConfig() : EmptyHttpFilterConfig("add-trailers-filter") {}
 
-  Http::FilterFactoryCb createFilter(const std::string&, Server::Configuration::FactoryContext&) {
+  Http::FilterFactoryCb createFilter(const std::string&,
+                                     Server::Configuration::FactoryContext&) override {
     return [](Http::FilterChainFactoryCallbacks& callbacks) -> void {
       callbacks.addStreamFilter(std::make_shared<::Envoy::AddTrailersStreamFilter>());
     };
diff --git a/test/integration/filters/clear_route_cache_filter.cc b/test/integration/filters/clear_route_cache_filter.cc
index 1e7f72cf6627..94f75d1beb61 100644
--- a/test/integration/filters/clear_route_cache_filter.cc
+++ b/test/integration/filters/clear_route_cache_filter.cc
@@ -22,7 +22,8 @@ class ClearRouteCacheFilterConfig : public Extensions::HttpFilters::Common::Empt
 public:
   ClearRouteCacheFilterConfig() : EmptyHttpFilterConfig("clear-route-cache") {}
 
-  Http::FilterFactoryCb createFilter(const std::string&, Server::Configuration::FactoryContext&) {
+  Http::FilterFactoryCb createFilter(const std::string&,
+                                     Server::Configuration::FactoryContext&) override {
     return [](Http::FilterChainFactoryCallbacks& callbacks) -> void {
       callbacks.addStreamFilter(std::make_shared<::Envoy::ClearRouteCacheFilter>());
     };
diff --git a/test/integration/filters/common.h b/test/integration/filters/common.h
index 524fbce49272..247e756d5e45 100644
--- a/test/integration/filters/common.h
+++ b/test/integration/filters/common.h
@@ -15,7 +15,8 @@ class SimpleFilterConfig : public Extensions::HttpFilters::Common::EmptyHttpFilt
 public:
   SimpleFilterConfig() : EmptyHttpFilterConfig(T::name) {}
 
-  Http::FilterFactoryCb createFilter(const std::string&, Server::Configuration::FactoryContext&) {
+  Http::FilterFactoryCb createFilter(const std::string&,
+                                     Server::Configuration::FactoryContext&) override {
     return [](Http::FilterChainFactoryCallbacks& callbacks) -> void {
       callbacks.addStreamFilter(std::make_shared<T>());
     };
diff --git a/test/integration/filters/modify_buffer_filter.cc b/test/integration/filters/modify_buffer_filter.cc
index 82fc65d6ffe9..f96a258b09ce 100644
--- a/test/integration/filters/modify_buffer_filter.cc
+++ b/test/integration/filters/modify_buffer_filter.cc
@@ -13,7 +13,7 @@ namespace Envoy {
 // the content of the filter buffer.
 class ModifyBufferStreamFilter : public Http::PassThroughFilter {
 public:
-  Http::FilterDataStatus decodeData(Buffer::Instance& data, bool end_stream) {
+  Http::FilterDataStatus decodeData(Buffer::Instance& data, bool end_stream) override {
     decoder_callbacks_->addDecodedData(data, true);
 
     if (end_stream) {
@@ -27,7 +27,7 @@ class ModifyBufferStreamFilter : public Http::PassThroughFilter {
     return Http::FilterDataStatus::StopIterationNoBuffer;
   }
 
-  Http::FilterDataStatus encodeData(Buffer::Instance& data, bool end_stream) {
+  Http::FilterDataStatus encodeData(Buffer::Instance& data, bool end_stream) override {
     encoder_callbacks_->addEncodedData(data, true);
 
     if (end_stream) {
@@ -46,7 +46,8 @@ class ModifyBuffferFilterConfig : public Extensions::HttpFilters::Common::EmptyH
 public:
   ModifyBuffferFilterConfig() : EmptyHttpFilterConfig("modify-buffer-filter") {}
 
-  Http::FilterFactoryCb createFilter(const std::string&, Server::Configuration::FactoryContext&) {
+  Http::FilterFactoryCb createFilter(const std::string&,
+                                     Server::Configuration::FactoryContext&) override {
     return [](Http::FilterChainFactoryCallbacks& callbacks) -> void {
       callbacks.addStreamFilter(std::make_shared<::Envoy::ModifyBufferStreamFilter>());
     };
diff --git a/test/integration/filters/pause_filter.cc b/test/integration/filters/pause_filter.cc
index 228dce27f725..8ed74d4198b8 100644
--- a/test/integration/filters/pause_filter.cc
+++ b/test/integration/filters/pause_filter.cc
@@ -63,7 +63,8 @@ class TestPauseFilterConfig : public Extensions::HttpFilters::Common::EmptyHttpF
 public:
   TestPauseFilterConfig() : EmptyHttpFilterConfig("pause-filter") {}
 
-  Http::FilterFactoryCb createFilter(const std::string&, Server::Configuration::FactoryContext&) {
+  Http::FilterFactoryCb createFilter(const std::string&,
+                                     Server::Configuration::FactoryContext&) override {
     return [&](Http::FilterChainFactoryCallbacks& callbacks) -> void {
       // GUARDED_BY insists the lock be held when the guarded variables are passed by reference.
       absl::WriterMutexLock m(&encode_lock_);
diff --git a/test/integration/filters/random_pause_filter.cc b/test/integration/filters/random_pause_filter.cc
index 15f3f71e160e..b709da758ce9 100644
--- a/test/integration/filters/random_pause_filter.cc
+++ b/test/integration/filters/random_pause_filter.cc
@@ -49,7 +49,8 @@ class RandomPauseFilterConfig : public Extensions::HttpFilters::Common::EmptyHtt
 public:
   RandomPauseFilterConfig() : EmptyHttpFilterConfig("random-pause-filter") {}
 
-  Http::FilterFactoryCb createFilter(const std::string&, Server::Configuration::FactoryContext&) {
+  Http::FilterFactoryCb createFilter(const std::string&,
+                                     Server::Configuration::FactoryContext&) override {
     return [&](Http::FilterChainFactoryCallbacks& callbacks) -> void {
       absl::WriterMutexLock m(&rand_lock_);
       if (rng_ == nullptr) {
diff --git a/test/integration/filters/request_metadata_filter.cc b/test/integration/filters/request_metadata_filter.cc
index 19c6425bdc3a..b3823542213d 100644
--- a/test/integration/filters/request_metadata_filter.cc
+++ b/test/integration/filters/request_metadata_filter.cc
@@ -51,7 +51,8 @@ class AddRequestMetadataStreamFilterConfig
     : public Extensions::HttpFilters::Common::EmptyHttpFilterConfig {
 public:
   AddRequestMetadataStreamFilterConfig() : EmptyHttpFilterConfig("request-metadata-filter") {}
-  Http::FilterFactoryCb createFilter(const std::string&, Server::Configuration::FactoryContext&) {
+  Http::FilterFactoryCb createFilter(const std::string&,
+                                     Server::Configuration::FactoryContext&) override {
     return [](Http::FilterChainFactoryCallbacks& callbacks) -> void {
       callbacks.addStreamFilter(std::make_shared<::Envoy::RequestMetadataStreamFilter>());
     };
diff --git a/test/integration/filters/response_metadata_filter.cc b/test/integration/filters/response_metadata_filter.cc
index 4d5f45f07a3c..bc3779d3692e 100644
--- a/test/integration/filters/response_metadata_filter.cc
+++ b/test/integration/filters/response_metadata_filter.cc
@@ -83,7 +83,8 @@ class AddMetadataStreamFilterConfig
 public:
   AddMetadataStreamFilterConfig() : EmptyHttpFilterConfig("response-metadata-filter") {}
 
-  Http::FilterFactoryCb createFilter(const std::string&, Server::Configuration::FactoryContext&) {
+  Http::FilterFactoryCb createFilter(const std::string&,
+                                     Server::Configuration::FactoryContext&) override {
     return [](Http::FilterChainFactoryCallbacks& callbacks) -> void {
       callbacks.addStreamFilter(std::make_shared<::Envoy::ResponseMetadataStreamFilter>());
     };
diff --git a/test/integration/filters/stop_iteration_and_continue_filter.cc b/test/integration/filters/stop_iteration_and_continue_filter.cc
index b86cccbb1396..f90f9d483182 100644
--- a/test/integration/filters/stop_iteration_and_continue_filter.cc
+++ b/test/integration/filters/stop_iteration_and_continue_filter.cc
@@ -12,7 +12,7 @@ namespace Envoy {
 // A test filter that does StopIterationNoBuffer then continues after a 0ms alarm.
 class StopIterationAndContinueFilter : public Http::PassThroughFilter {
 public:
-  Http::FilterDataStatus decodeData(Buffer::Instance&, bool end_stream) {
+  Http::FilterDataStatus decodeData(Buffer::Instance&, bool end_stream) override {
     RELEASE_ASSERT(!end_stream_seen_, "end stream seen twice");
     if (end_stream) {
       end_stream_seen_ = true;
@@ -33,7 +33,8 @@ class StopIterationAndContinueFilterConfig
   StopIterationAndContinueFilterConfig()
       : EmptyHttpFilterConfig("stop-iteration-and-continue-filter") {}
 
-  Http::FilterFactoryCb createFilter(const std::string&, Server::Configuration::FactoryContext&) {
+  Http::FilterFactoryCb createFilter(const std::string&,
+                                     Server::Configuration::FactoryContext&) override {
     return [](Http::FilterChainFactoryCallbacks& callbacks) -> void {
       callbacks.addStreamFilter(std::make_shared<::Envoy::StopIterationAndContinueFilter>());
     };
diff --git a/test/integration/http_integration.h b/test/integration/http_integration.h
index 2df23c0462d0..bbeda044911e 100644
--- a/test/integration/http_integration.h
+++ b/test/integration/http_integration.h
@@ -98,7 +98,7 @@ class HttpIntegrationTest : public BaseIntegrationTest {
                       const InstanceConstSharedPtrFn& upstream_address_fn,
                       Network::Address::IpVersion version,
                       const std::string& config = ConfigHelper::HTTP_PROXY_CONFIG);
-  virtual ~HttpIntegrationTest();
+  ~HttpIntegrationTest() override;
 
   // Waits for the first access log entry.
   std::string waitForAccessLog(const std::string& filename);
diff --git a/test/integration/server.h b/test/integration/server.h
index 3cc7489cad55..55e3c11eab23 100644
--- a/test/integration/server.h
+++ b/test/integration/server.h
@@ -236,7 +236,7 @@ class IntegrationTestServer : public Logger::Loggable<Logger::Id::testing>,
          absl::optional<std::reference_wrapper<ProcessObject>> process_object = absl::nullopt);
   // Note that the derived class is responsible for tearing down the server in its
   // destructor.
-  ~IntegrationTestServer();
+  ~IntegrationTestServer() override;
 
   void waitUntilListenersReady();
 
diff --git a/test/mocks/access_log/mocks.h b/test/mocks/access_log/mocks.h
index 562d817e896b..51748550b559 100644
--- a/test/mocks/access_log/mocks.h
+++ b/test/mocks/access_log/mocks.h
@@ -13,7 +13,7 @@ namespace AccessLog {
 class MockAccessLogFile : public AccessLogFile {
 public:
   MockAccessLogFile();
-  ~MockAccessLogFile();
+  ~MockAccessLogFile() override;
 
   // AccessLog::AccessLogFile
   MOCK_METHOD1(write, void(absl::string_view data));
@@ -24,7 +24,7 @@ class MockAccessLogFile : public AccessLogFile {
 class MockFilter : public Filter {
 public:
   MockFilter();
-  ~MockFilter();
+  ~MockFilter() override;
 
   // AccessLog::Filter
   MOCK_METHOD4(evaluate,
@@ -36,7 +36,7 @@ class MockFilter : public Filter {
 class MockAccessLogManager : public AccessLogManager {
 public:
   MockAccessLogManager();
-  ~MockAccessLogManager();
+  ~MockAccessLogManager() override;
 
   // AccessLog::AccessLogManager
   MOCK_METHOD0(reopen, void());
@@ -48,7 +48,7 @@ class MockAccessLogManager : public AccessLogManager {
 class MockInstance : public Instance {
 public:
   MockInstance();
-  ~MockInstance();
+  ~MockInstance() override;
 
   // AccessLog::Instance
   MOCK_METHOD4(log,
diff --git a/test/mocks/api/mocks.h b/test/mocks/api/mocks.h
index 4bda9755288a..a85587a62683 100644
--- a/test/mocks/api/mocks.h
+++ b/test/mocks/api/mocks.h
@@ -26,7 +26,7 @@ namespace Api {
 class MockApi : public Api {
 public:
   MockApi();
-  ~MockApi();
+  ~MockApi() override;
 
   // Api::Api
   Event::DispatcherPtr allocateDispatcher() override;
@@ -49,7 +49,7 @@ class MockApi : public Api {
 class MockOsSysCalls : public OsSysCallsImpl {
 public:
   MockOsSysCalls();
-  ~MockOsSysCalls();
+  ~MockOsSysCalls() override;
 
   // Api::OsSysCalls
   SysCallIntResult setsockopt(int sockfd, int level, int optname, const void* optval,
diff --git a/test/mocks/buffer/mocks.h b/test/mocks/buffer/mocks.h
index 6713259969f7..2f9eb963eca4 100644
--- a/test/mocks/buffer/mocks.h
+++ b/test/mocks/buffer/mocks.h
@@ -90,7 +90,7 @@ class MockWatermarkBuffer : public MockBufferBase<Buffer::WatermarkBuffer> {
 class MockBufferFactory : public Buffer::WatermarkFactory {
 public:
   MockBufferFactory();
-  ~MockBufferFactory();
+  ~MockBufferFactory() override;
 
   Buffer::InstancePtr create(std::function<void()> below_low,
                              std::function<void()> above_high) override {
diff --git a/test/mocks/common.h b/test/mocks/common.h
index 77637b83ade2..2bc37836c50e 100644
--- a/test/mocks/common.h
+++ b/test/mocks/common.h
@@ -43,7 +43,7 @@ class ReadyWatcher {
 class MockTimeSystem : public Event::TestTimeSystem {
 public:
   MockTimeSystem();
-  ~MockTimeSystem();
+  ~MockTimeSystem() override;
 
   // TODO(#4160): Eliminate all uses of MockTimeSystem, replacing with SimulatedTimeSystem,
   // where timer callbacks are triggered by the advancement of time. This implementation
diff --git a/test/mocks/event/mocks.h b/test/mocks/event/mocks.h
index 5cbd2f076f5f..ad190e23e939 100644
--- a/test/mocks/event/mocks.h
+++ b/test/mocks/event/mocks.h
@@ -28,7 +28,7 @@ namespace Event {
 class MockDispatcher : public Dispatcher {
 public:
   MockDispatcher();
-  ~MockDispatcher();
+  ~MockDispatcher() override;
 
   // Dispatcher
   TimeSource& timeSource() override { return time_system_; }
@@ -125,7 +125,7 @@ class MockTimer : public Timer {
 public:
   MockTimer();
   MockTimer(MockDispatcher* dispatcher);
-  ~MockTimer();
+  ~MockTimer() override;
 
   void invokeCallback() {
     EXPECT_TRUE(enabled_);
@@ -147,7 +147,7 @@ class MockTimer : public Timer {
 class MockSignalEvent : public SignalEvent {
 public:
   MockSignalEvent(MockDispatcher* dispatcher);
-  ~MockSignalEvent();
+  ~MockSignalEvent() override;
 
   SignalCb callback_;
 };
@@ -155,7 +155,7 @@ class MockSignalEvent : public SignalEvent {
 class MockFileEvent : public FileEvent {
 public:
   MockFileEvent();
-  ~MockFileEvent();
+  ~MockFileEvent() override;
 
   MOCK_METHOD1(activate, void(uint32_t events));
   MOCK_METHOD1(setEnabled, void(uint32_t events));
diff --git a/test/mocks/grpc/mocks.h b/test/mocks/grpc/mocks.h
index f851f0e0176d..a2393b32444a 100644
--- a/test/mocks/grpc/mocks.h
+++ b/test/mocks/grpc/mocks.h
@@ -19,7 +19,7 @@ namespace Grpc {
 class MockAsyncRequest : public AsyncRequest {
 public:
   MockAsyncRequest();
-  ~MockAsyncRequest();
+  ~MockAsyncRequest() override;
 
   MOCK_METHOD0(cancel, void());
 };
@@ -27,9 +27,9 @@ class MockAsyncRequest : public AsyncRequest {
 class MockAsyncStream : public RawAsyncStream {
 public:
   MockAsyncStream();
-  ~MockAsyncStream();
+  ~MockAsyncStream() override;
 
-  void sendMessageRaw(Buffer::InstancePtr&& request, bool end_stream) {
+  void sendMessageRaw(Buffer::InstancePtr&& request, bool end_stream) override {
     sendMessageRaw_(request, end_stream);
   }
   MOCK_METHOD2_T(sendMessageRaw_, void(Buffer::InstancePtr& request, bool end_stream));
@@ -85,7 +85,7 @@ class MockAsyncClient : public RawAsyncClient {
 class MockAsyncClientFactory : public AsyncClientFactory {
 public:
   MockAsyncClientFactory();
-  ~MockAsyncClientFactory();
+  ~MockAsyncClientFactory() override;
 
   MOCK_METHOD0(create, RawAsyncClientPtr());
 };
@@ -93,7 +93,7 @@ class MockAsyncClientFactory : public AsyncClientFactory {
 class MockAsyncClientManager : public AsyncClientManager {
 public:
   MockAsyncClientManager();
-  ~MockAsyncClientManager();
+  ~MockAsyncClientManager() override;
 
   MOCK_METHOD3(factoryForGrpcService,
                AsyncClientFactoryPtr(const envoy::api::v2::core::GrpcService& grpc_service,
diff --git a/test/mocks/http/conn_pool.h b/test/mocks/http/conn_pool.h
index 18ea24063c56..60566c96b129 100644
--- a/test/mocks/http/conn_pool.h
+++ b/test/mocks/http/conn_pool.h
@@ -14,7 +14,7 @@ class MockCancellable : public Cancellable {
 
 public:
   MockCancellable();
-  ~MockCancellable();
+  ~MockCancellable() override;
 
   // Http::ConnectionPool::Cancellable
   MOCK_METHOD0(cancel, void());
@@ -23,7 +23,7 @@ class MockCancellable : public Cancellable {
 class MockInstance : public Instance {
 public:
   MockInstance();
-  ~MockInstance();
+  ~MockInstance() override;
 
   // Http::ConnectionPool::Instance
   MOCK_CONST_METHOD0(protocol, Http::Protocol());
diff --git a/test/mocks/http/mocks.h b/test/mocks/http/mocks.h
index a3a3f53768c9..34cb97b465b9 100644
--- a/test/mocks/http/mocks.h
+++ b/test/mocks/http/mocks.h
@@ -41,7 +41,7 @@ namespace Http {
 class MockConnectionCallbacks : public virtual ConnectionCallbacks {
 public:
   MockConnectionCallbacks();
-  ~MockConnectionCallbacks();
+  ~MockConnectionCallbacks() override;
 
   // Http::ConnectionCallbacks
   MOCK_METHOD0(onGoAway, void());
@@ -51,7 +51,7 @@ class MockServerConnectionCallbacks : public ServerConnectionCallbacks,
                                       public MockConnectionCallbacks {
 public:
   MockServerConnectionCallbacks();
-  ~MockServerConnectionCallbacks();
+  ~MockServerConnectionCallbacks() override;
 
   // Http::ServerConnectionCallbacks
   MOCK_METHOD2(newStream,
@@ -61,7 +61,7 @@ class MockServerConnectionCallbacks : public ServerConnectionCallbacks,
 class MockStreamCallbacks : public StreamCallbacks {
 public:
   MockStreamCallbacks();
-  ~MockStreamCallbacks();
+  ~MockStreamCallbacks() override;
 
   // Http::StreamCallbacks
   MOCK_METHOD2(onResetStream, void(StreamResetReason reason, absl::string_view));
@@ -72,7 +72,7 @@ class MockStreamCallbacks : public StreamCallbacks {
 class MockServerConnection : public ServerConnection {
 public:
   MockServerConnection();
-  ~MockServerConnection();
+  ~MockServerConnection() override;
 
   // Http::Connection
   MOCK_METHOD1(dispatch, void(Buffer::Instance& data));
@@ -89,7 +89,7 @@ class MockServerConnection : public ServerConnection {
 class MockClientConnection : public ClientConnection {
 public:
   MockClientConnection();
-  ~MockClientConnection();
+  ~MockClientConnection() override;
 
   // Http::Connection
   MOCK_METHOD1(dispatch, void(Buffer::Instance& data));
@@ -107,7 +107,7 @@ class MockClientConnection : public ClientConnection {
 class MockFilterChainFactory : public FilterChainFactory {
 public:
   MockFilterChainFactory();
-  ~MockFilterChainFactory();
+  ~MockFilterChainFactory() override;
 
   // Http::FilterChainFactory
   MOCK_METHOD1(createFilterChain, void(FilterChainFactoryCallbacks& callbacks));
@@ -128,7 +128,7 @@ class MockStreamDecoderFilterCallbacks : public StreamDecoderFilterCallbacks,
                                          public MockStreamFilterCallbacksBase {
 public:
   MockStreamDecoderFilterCallbacks();
-  ~MockStreamDecoderFilterCallbacks();
+  ~MockStreamDecoderFilterCallbacks() override;
 
   // Http::StreamFilterCallbacks
   MOCK_METHOD0(connection, const Network::Connection*());
@@ -199,7 +199,7 @@ class MockStreamEncoderFilterCallbacks : public StreamEncoderFilterCallbacks,
                                          public MockStreamFilterCallbacksBase {
 public:
   MockStreamEncoderFilterCallbacks();
-  ~MockStreamEncoderFilterCallbacks();
+  ~MockStreamEncoderFilterCallbacks() override;
 
   // Http::StreamFilterCallbacks
   MOCK_METHOD0(connection, const Network::Connection*());
@@ -233,7 +233,7 @@ class MockStreamEncoderFilterCallbacks : public StreamEncoderFilterCallbacks,
 class MockStreamDecoderFilter : public StreamDecoderFilter {
 public:
   MockStreamDecoderFilter();
-  ~MockStreamDecoderFilter();
+  ~MockStreamDecoderFilter() override;
 
   // Http::StreamFilterBase
   MOCK_METHOD0(onDestroy, void());
@@ -252,7 +252,7 @@ class MockStreamDecoderFilter : public StreamDecoderFilter {
 class MockStreamEncoderFilter : public StreamEncoderFilter {
 public:
   MockStreamEncoderFilter();
-  ~MockStreamEncoderFilter();
+  ~MockStreamEncoderFilter() override;
 
   // Http::StreamFilterBase
   MOCK_METHOD0(onDestroy, void());
@@ -272,7 +272,7 @@ class MockStreamEncoderFilter : public StreamEncoderFilter {
 class MockStreamFilter : public StreamFilter {
 public:
   MockStreamFilter();
-  ~MockStreamFilter();
+  ~MockStreamFilter() override;
 
   // Http::StreamFilterBase
   MOCK_METHOD0(onDestroy, void());
@@ -299,7 +299,7 @@ class MockStreamFilter : public StreamFilter {
 class MockAsyncClient : public AsyncClient {
 public:
   MockAsyncClient();
-  ~MockAsyncClient();
+  ~MockAsyncClient() override;
 
   MOCK_METHOD0(onRequestDestroy, void());
 
@@ -321,7 +321,7 @@ class MockAsyncClient : public AsyncClient {
 class MockAsyncClientCallbacks : public AsyncClient::Callbacks {
 public:
   MockAsyncClientCallbacks();
-  ~MockAsyncClientCallbacks();
+  ~MockAsyncClientCallbacks() override;
 
   void onSuccess(MessagePtr&& response) override { onSuccess_(response.get()); }
 
@@ -333,7 +333,7 @@ class MockAsyncClientCallbacks : public AsyncClient::Callbacks {
 class MockAsyncClientStreamCallbacks : public AsyncClient::StreamCallbacks {
 public:
   MockAsyncClientStreamCallbacks();
-  ~MockAsyncClientStreamCallbacks();
+  ~MockAsyncClientStreamCallbacks() override;
 
   void onHeaders(HeaderMapPtr&& headers, bool end_stream) override {
     onHeaders_(*headers, end_stream);
@@ -349,7 +349,7 @@ class MockAsyncClientStreamCallbacks : public AsyncClient::StreamCallbacks {
 class MockAsyncClientRequest : public AsyncClient::Request {
 public:
   MockAsyncClientRequest(MockAsyncClient* client);
-  ~MockAsyncClientRequest();
+  ~MockAsyncClientRequest() override;
 
   MOCK_METHOD0(cancel, void());
 
@@ -359,7 +359,7 @@ class MockAsyncClientRequest : public AsyncClient::Request {
 class MockAsyncClientStream : public AsyncClient::Stream {
 public:
   MockAsyncClientStream();
-  ~MockAsyncClientStream();
+  ~MockAsyncClientStream() override;
 
   MOCK_METHOD2(sendHeaders, void(HeaderMap& headers, bool end_stream));
   MOCK_METHOD2(sendData, void(Buffer::Instance& data, bool end_stream));
@@ -370,7 +370,7 @@ class MockAsyncClientStream : public AsyncClient::Stream {
 class MockFilterChainFactoryCallbacks : public Http::FilterChainFactoryCallbacks {
 public:
   MockFilterChainFactoryCallbacks();
-  ~MockFilterChainFactoryCallbacks();
+  ~MockFilterChainFactoryCallbacks() override;
 
   MOCK_METHOD1(addStreamDecoderFilter, void(Http::StreamDecoderFilterSharedPtr filter));
   MOCK_METHOD1(addStreamEncoderFilter, void(Http::StreamEncoderFilterSharedPtr filter));
diff --git a/test/mocks/http/stream_encoder.h b/test/mocks/http/stream_encoder.h
index 5c2e067979e5..bc9138e37746 100644
--- a/test/mocks/http/stream_encoder.h
+++ b/test/mocks/http/stream_encoder.h
@@ -12,7 +12,7 @@ namespace Http {
 class MockStreamEncoder : public StreamEncoder {
 public:
   MockStreamEncoder();
-  ~MockStreamEncoder();
+  ~MockStreamEncoder() override;
 
   // Http::StreamEncoder
   MOCK_METHOD1(encode100ContinueHeaders, void(const HeaderMap& headers));
diff --git a/test/mocks/local_info/mocks.h b/test/mocks/local_info/mocks.h
index 6c53a2c19a3f..655eaaf59030 100644
--- a/test/mocks/local_info/mocks.h
+++ b/test/mocks/local_info/mocks.h
@@ -12,7 +12,7 @@ namespace LocalInfo {
 class MockLocalInfo : public LocalInfo {
 public:
   MockLocalInfo();
-  ~MockLocalInfo();
+  ~MockLocalInfo() override;
 
   MOCK_CONST_METHOD0(address, Network::Address::InstanceConstSharedPtr());
   MOCK_CONST_METHOD0(zoneName, const std::string&());
diff --git a/test/mocks/network/connection.h b/test/mocks/network/connection.h
index 880802982a11..f660269de13a 100644
--- a/test/mocks/network/connection.h
+++ b/test/mocks/network/connection.h
@@ -17,7 +17,7 @@ namespace Network {
 class MockConnectionCallbacks : public ConnectionCallbacks {
 public:
   MockConnectionCallbacks();
-  ~MockConnectionCallbacks();
+  ~MockConnectionCallbacks() override;
 
   // Network::ConnectionCallbacks
   MOCK_METHOD1(onEvent, void(Network::ConnectionEvent event));
@@ -48,7 +48,7 @@ class MockConnectionBase {
 class MockConnection : public Connection, public MockConnectionBase {
 public:
   MockConnection();
-  ~MockConnection();
+  ~MockConnection() override;
 
   // Network::Connection
   MOCK_METHOD1(addConnectionCallbacks, void(ConnectionCallbacks& cb));
@@ -94,7 +94,7 @@ class MockConnection : public Connection, public MockConnectionBase {
 class MockClientConnection : public ClientConnection, public MockConnectionBase {
 public:
   MockClientConnection();
-  ~MockClientConnection();
+  ~MockClientConnection() override;
 
   // Network::Connection
   MOCK_METHOD1(addConnectionCallbacks, void(ConnectionCallbacks& cb));
@@ -143,7 +143,7 @@ class MockClientConnection : public ClientConnection, public MockConnectionBase
 class MockFilterManagerConnection : public FilterManagerConnection, public MockConnectionBase {
 public:
   MockFilterManagerConnection();
-  ~MockFilterManagerConnection();
+  ~MockFilterManagerConnection() override;
 
   // Network::Connection
   MOCK_METHOD1(addConnectionCallbacks, void(ConnectionCallbacks& cb));
diff --git a/test/mocks/network/mocks.h b/test/mocks/network/mocks.h
index 28e12f6f4d02..00f9b902386b 100644
--- a/test/mocks/network/mocks.h
+++ b/test/mocks/network/mocks.h
@@ -29,7 +29,7 @@ namespace Network {
 class MockActiveDnsQuery : public ActiveDnsQuery {
 public:
   MockActiveDnsQuery();
-  ~MockActiveDnsQuery();
+  ~MockActiveDnsQuery() override;
 
   // Network::ActiveDnsQuery
   MOCK_METHOD0(cancel, void());
@@ -38,7 +38,7 @@ class MockActiveDnsQuery : public ActiveDnsQuery {
 class MockDnsResolver : public DnsResolver {
 public:
   MockDnsResolver();
-  ~MockDnsResolver();
+  ~MockDnsResolver() override;
 
   // Network::DnsResolver
   MOCK_METHOD3(resolve, ActiveDnsQuery*(const std::string& dns_name,
@@ -50,7 +50,7 @@ class MockDnsResolver : public DnsResolver {
 class MockAddressResolver : public Address::Resolver {
 public:
   MockAddressResolver();
-  ~MockAddressResolver();
+  ~MockAddressResolver() override;
 
   MOCK_METHOD1(resolve,
                Address::InstanceConstSharedPtr(const envoy::api::v2::core::SocketAddress&));
@@ -60,7 +60,7 @@ class MockAddressResolver : public Address::Resolver {
 class MockReadFilterCallbacks : public ReadFilterCallbacks {
 public:
   MockReadFilterCallbacks();
-  ~MockReadFilterCallbacks();
+  ~MockReadFilterCallbacks() override;
 
   MOCK_METHOD0(connection, Connection&());
   MOCK_METHOD0(continueReading, void());
@@ -75,7 +75,7 @@ class MockReadFilterCallbacks : public ReadFilterCallbacks {
 class MockReadFilter : public ReadFilter {
 public:
   MockReadFilter();
-  ~MockReadFilter();
+  ~MockReadFilter() override;
 
   MOCK_METHOD2(onData, FilterStatus(Buffer::Instance& data, bool end_stream));
   MOCK_METHOD0(onNewConnection, FilterStatus());
@@ -87,7 +87,7 @@ class MockReadFilter : public ReadFilter {
 class MockWriteFilterCallbacks : public WriteFilterCallbacks {
 public:
   MockWriteFilterCallbacks();
-  ~MockWriteFilterCallbacks();
+  ~MockWriteFilterCallbacks() override;
 
   MOCK_METHOD0(connection, Connection&());
   MOCK_METHOD2(injectWriteDataToFilterChain, void(Buffer::Instance& data, bool end_stream));
@@ -98,7 +98,7 @@ class MockWriteFilterCallbacks : public WriteFilterCallbacks {
 class MockWriteFilter : public WriteFilter {
 public:
   MockWriteFilter();
-  ~MockWriteFilter();
+  ~MockWriteFilter() override;
 
   MOCK_METHOD2(onWrite, FilterStatus(Buffer::Instance& data, bool end_stream));
   MOCK_METHOD1(initializeWriteFilterCallbacks, void(WriteFilterCallbacks& callbacks));
@@ -109,7 +109,7 @@ class MockWriteFilter : public WriteFilter {
 class MockFilter : public Filter {
 public:
   MockFilter();
-  ~MockFilter();
+  ~MockFilter() override;
 
   MOCK_METHOD2(onData, FilterStatus(Buffer::Instance& data, bool end_stream));
   MOCK_METHOD0(onNewConnection, FilterStatus());
@@ -124,7 +124,7 @@ class MockFilter : public Filter {
 class MockListenerCallbacks : public ListenerCallbacks {
 public:
   MockListenerCallbacks();
-  ~MockListenerCallbacks();
+  ~MockListenerCallbacks() override;
 
   void onAccept(ConnectionSocketPtr&& socket, bool redirected) override {
     onAccept_(socket, redirected);
@@ -138,7 +138,7 @@ class MockListenerCallbacks : public ListenerCallbacks {
 class MockUdpListenerCallbacks : public UdpListenerCallbacks {
 public:
   MockUdpListenerCallbacks();
-  ~MockUdpListenerCallbacks();
+  ~MockUdpListenerCallbacks() override;
 
   void onData(UdpRecvData& data) override { onData_(data); }
 
@@ -158,7 +158,7 @@ class MockUdpListenerCallbacks : public UdpListenerCallbacks {
 class MockDrainDecision : public DrainDecision {
 public:
   MockDrainDecision();
-  ~MockDrainDecision();
+  ~MockDrainDecision() override;
 
   MOCK_CONST_METHOD0(drainClose, bool());
 };
@@ -166,7 +166,7 @@ class MockDrainDecision : public DrainDecision {
 class MockListenerFilter : public ListenerFilter {
 public:
   MockListenerFilter();
-  ~MockListenerFilter();
+  ~MockListenerFilter() override;
 
   MOCK_METHOD1(onAccept, Network::FilterStatus(ListenerFilterCallbacks&));
 };
@@ -174,7 +174,7 @@ class MockListenerFilter : public ListenerFilter {
 class MockListenerFilterManager : public ListenerFilterManager {
 public:
   MockListenerFilterManager();
-  ~MockListenerFilterManager();
+  ~MockListenerFilterManager() override;
 
   void addAcceptFilter(ListenerFilterPtr&& filter) override { addAcceptFilter_(filter); }
 
@@ -184,7 +184,7 @@ class MockListenerFilterManager : public ListenerFilterManager {
 class MockFilterChain : public FilterChain {
 public:
   MockFilterChain();
-  ~MockFilterChain();
+  ~MockFilterChain() override;
 
   // Network::FilterChain
   MOCK_CONST_METHOD0(transportSocketFactory, const TransportSocketFactory&());
@@ -194,7 +194,7 @@ class MockFilterChain : public FilterChain {
 class MockFilterChainManager : public FilterChainManager {
 public:
   MockFilterChainManager();
-  ~MockFilterChainManager();
+  ~MockFilterChainManager() override;
 
   // Network::FilterChainManager
   MOCK_CONST_METHOD1(findFilterChain, const FilterChain*(const ConnectionSocket& socket));
@@ -203,7 +203,7 @@ class MockFilterChainManager : public FilterChainManager {
 class MockFilterChainFactory : public FilterChainFactory {
 public:
   MockFilterChainFactory();
-  ~MockFilterChainFactory();
+  ~MockFilterChainFactory() override;
 
   MOCK_METHOD2(createNetworkFilterChain,
                bool(Connection& connection,
@@ -239,7 +239,7 @@ class MockListenSocket : public Socket {
 class MockSocketOption : public Socket::Option {
 public:
   MockSocketOption();
-  ~MockSocketOption();
+  ~MockSocketOption() override;
 
   MOCK_CONST_METHOD2(setOption,
                      bool(Socket&, envoy::api::v2::core::SocketOption::SocketState state));
@@ -285,7 +285,7 @@ class MockConnectionSocket : public ConnectionSocket {
 class MockListenerFilterCallbacks : public ListenerFilterCallbacks {
 public:
   MockListenerFilterCallbacks();
-  ~MockListenerFilterCallbacks();
+  ~MockListenerFilterCallbacks() override;
 
   MOCK_METHOD0(socket, ConnectionSocket&());
   MOCK_METHOD0(dispatcher, Event::Dispatcher&());
@@ -297,7 +297,7 @@ class MockListenerFilterCallbacks : public ListenerFilterCallbacks {
 class MockListenerConfig : public ListenerConfig {
 public:
   MockListenerConfig();
-  ~MockListenerConfig();
+  ~MockListenerConfig() override;
 
   MOCK_METHOD0(filterChainManager, FilterChainManager&());
   MOCK_METHOD0(filterChainFactory, FilterChainFactory&());
@@ -320,7 +320,7 @@ class MockListenerConfig : public ListenerConfig {
 class MockListener : public Listener {
 public:
   MockListener();
-  ~MockListener();
+  ~MockListener() override;
 
   MOCK_METHOD0(onDestroy, void());
   MOCK_METHOD0(enable, void());
@@ -330,7 +330,7 @@ class MockListener : public Listener {
 class MockConnectionHandler : public ConnectionHandler {
 public:
   MockConnectionHandler();
-  ~MockConnectionHandler();
+  ~MockConnectionHandler() override;
 
   MOCK_METHOD0(numConnections, uint64_t());
   MOCK_METHOD1(addListener, void(ListenerConfig& config));
@@ -346,7 +346,7 @@ class MockConnectionHandler : public ConnectionHandler {
 class MockIp : public Address::Ip {
 public:
   MockIp();
-  ~MockIp();
+  ~MockIp() override;
 
   MOCK_CONST_METHOD0(addressAsString, const std::string&());
   MOCK_CONST_METHOD0(isAnyAddress, bool());
@@ -361,7 +361,7 @@ class MockResolvedAddress : public Address::Instance {
 public:
   MockResolvedAddress(const std::string& logical, const std::string& physical)
       : logical_(logical), physical_(physical) {}
-  ~MockResolvedAddress();
+  ~MockResolvedAddress() override;
 
   bool operator==(const Address::Instance& other) const override {
     return asString() == other.asString();
@@ -385,7 +385,7 @@ class MockResolvedAddress : public Address::Instance {
 class MockTransportSocket : public TransportSocket {
 public:
   MockTransportSocket();
-  ~MockTransportSocket();
+  ~MockTransportSocket() override;
 
   MOCK_METHOD1(setTransportSocketCallbacks, void(TransportSocketCallbacks& callbacks));
   MOCK_CONST_METHOD0(protocol, std::string());
@@ -403,7 +403,7 @@ class MockTransportSocket : public TransportSocket {
 class MockTransportSocketFactory : public TransportSocketFactory {
 public:
   MockTransportSocketFactory();
-  ~MockTransportSocketFactory();
+  ~MockTransportSocketFactory() override;
 
   MOCK_CONST_METHOD0(implementsSecureTransport, bool());
   MOCK_CONST_METHOD1(createTransportSocket, TransportSocketPtr(TransportSocketOptionsSharedPtr));
@@ -412,7 +412,7 @@ class MockTransportSocketFactory : public TransportSocketFactory {
 class MockTransportSocketCallbacks : public TransportSocketCallbacks {
 public:
   MockTransportSocketCallbacks();
-  ~MockTransportSocketCallbacks();
+  ~MockTransportSocketCallbacks() override;
 
   MOCK_METHOD0(ioHandle, IoHandle&());
   MOCK_CONST_METHOD0(ioHandle, const IoHandle&());
@@ -427,7 +427,7 @@ class MockTransportSocketCallbacks : public TransportSocketCallbacks {
 class MockUdpListener : public UdpListener {
 public:
   MockUdpListener();
-  ~MockUdpListener();
+  ~MockUdpListener() override;
 
   MOCK_METHOD0(onDestroy, void());
   MOCK_METHOD0(enable, void());
@@ -440,7 +440,7 @@ class MockUdpListener : public UdpListener {
 class MockUdpReadFilterCallbacks : public UdpReadFilterCallbacks {
 public:
   MockUdpReadFilterCallbacks();
-  ~MockUdpReadFilterCallbacks();
+  ~MockUdpReadFilterCallbacks() override;
 
   MOCK_METHOD0(udpListener, UdpListener&());
 
@@ -450,7 +450,7 @@ class MockUdpReadFilterCallbacks : public UdpReadFilterCallbacks {
 class MockUdpListenerReadFilter : public UdpListenerReadFilter {
 public:
   MockUdpListenerReadFilter(UdpReadFilterCallbacks& callbacks);
-  ~MockUdpListenerReadFilter();
+  ~MockUdpListenerReadFilter() override;
 
   MOCK_METHOD1(onData, void(UdpRecvData&));
 };
@@ -458,7 +458,7 @@ class MockUdpListenerReadFilter : public UdpListenerReadFilter {
 class MockUdpListenerFilterManager : public UdpListenerFilterManager {
 public:
   MockUdpListenerFilterManager();
-  ~MockUdpListenerFilterManager();
+  ~MockUdpListenerFilterManager() override;
 
   void addReadFilter(UdpListenerReadFilterPtr&& filter) override { addReadFilter_(filter); }
 
diff --git a/test/mocks/protobuf/mocks.h b/test/mocks/protobuf/mocks.h
index 48c975e31ac1..66e2f5d2b9c1 100644
--- a/test/mocks/protobuf/mocks.h
+++ b/test/mocks/protobuf/mocks.h
@@ -10,7 +10,7 @@ namespace ProtobufMessage {
 class MockValidationVisitor : public ValidationVisitor {
 public:
   MockValidationVisitor();
-  ~MockValidationVisitor();
+  ~MockValidationVisitor() override;
 
   MOCK_METHOD1(onUnknownField, void(absl::string_view));
 };
diff --git a/test/mocks/router/mocks.h b/test/mocks/router/mocks.h
index f84aacda8ab8..aeda21400f98 100644
--- a/test/mocks/router/mocks.h
+++ b/test/mocks/router/mocks.h
@@ -34,7 +34,7 @@ namespace Router {
 class MockDirectResponseEntry : public DirectResponseEntry {
 public:
   MockDirectResponseEntry();
-  ~MockDirectResponseEntry();
+  ~MockDirectResponseEntry() override;
 
   // DirectResponseEntry
   MOCK_CONST_METHOD2(finalizeResponseHeaders,
@@ -112,7 +112,7 @@ class TestRetryPolicy : public RetryPolicy {
 class MockRetryState : public RetryState {
 public:
   MockRetryState();
-  ~MockRetryState();
+  ~MockRetryState() override;
 
   void expectHeadersRetry();
   void expectHedgedPerTryTimeoutRetry();
@@ -138,7 +138,7 @@ class MockRetryState : public RetryState {
 class MockRateLimitPolicyEntry : public RateLimitPolicyEntry {
 public:
   MockRateLimitPolicyEntry();
-  ~MockRateLimitPolicyEntry();
+  ~MockRateLimitPolicyEntry() override;
 
   // Router::RateLimitPolicyEntry
   MOCK_CONST_METHOD0(stage, uint64_t());
@@ -156,7 +156,7 @@ class MockRateLimitPolicyEntry : public RateLimitPolicyEntry {
 class MockRateLimitPolicy : public RateLimitPolicy {
 public:
   MockRateLimitPolicy();
-  ~MockRateLimitPolicy();
+  ~MockRateLimitPolicy() override;
 
   // Router::RateLimitPolicy
   MOCK_CONST_METHOD1(
@@ -182,7 +182,7 @@ class TestShadowPolicy : public ShadowPolicy {
 class MockShadowWriter : public ShadowWriter {
 public:
   MockShadowWriter();
-  ~MockShadowWriter();
+  ~MockShadowWriter() override;
 
   // Router::ShadowWriter
   void shadow(const std::string& cluster, Http::MessagePtr&& request,
@@ -206,7 +206,7 @@ class TestVirtualCluster : public VirtualCluster {
 class MockVirtualHost : public VirtualHost {
 public:
   MockVirtualHost();
-  ~MockVirtualHost();
+  ~MockVirtualHost() override;
 
   // Router::VirtualHost
   MOCK_CONST_METHOD0(name, const std::string&());
@@ -233,7 +233,7 @@ class MockVirtualHost : public VirtualHost {
 class MockHashPolicy : public HashPolicy {
 public:
   MockHashPolicy();
-  ~MockHashPolicy();
+  ~MockHashPolicy() override;
 
   // Router::HashPolicy
   MOCK_CONST_METHOD3(generateHash,
@@ -245,7 +245,7 @@ class MockHashPolicy : public HashPolicy {
 class MockMetadataMatchCriteria : public MetadataMatchCriteria {
 public:
   MockMetadataMatchCriteria();
-  ~MockMetadataMatchCriteria();
+  ~MockMetadataMatchCriteria() override;
 
   // Router::MetadataMatchCriteria
   MOCK_CONST_METHOD0(metadataMatchCriteria,
@@ -256,7 +256,7 @@ class MockMetadataMatchCriteria : public MetadataMatchCriteria {
 class MockPathMatchCriterion : public PathMatchCriterion {
 public:
   MockPathMatchCriterion();
-  ~MockPathMatchCriterion();
+  ~MockPathMatchCriterion() override;
 
   // Router::PathMatchCriterion
   MOCK_CONST_METHOD0(matchType, PathMatchType());
@@ -269,7 +269,7 @@ class MockPathMatchCriterion : public PathMatchCriterion {
 class MockRouteEntry : public RouteEntry {
 public:
   MockRouteEntry();
-  ~MockRouteEntry();
+  ~MockRouteEntry() override;
 
   // Router::Config
   MOCK_CONST_METHOD0(clusterName, const std::string&());
@@ -326,7 +326,7 @@ class MockRouteEntry : public RouteEntry {
 class MockDecorator : public Decorator {
 public:
   MockDecorator();
-  ~MockDecorator();
+  ~MockDecorator() override;
 
   // Router::Decorator
   MOCK_CONST_METHOD0(getOperation, const std::string&());
@@ -338,7 +338,7 @@ class MockDecorator : public Decorator {
 class MockRouteTracing : public RouteTracing {
 public:
   MockRouteTracing();
-  ~MockRouteTracing();
+  ~MockRouteTracing() override;
 
   // Router::RouteTracing
   MOCK_CONST_METHOD0(getClientSampling, const envoy::type::FractionalPercent&());
@@ -349,7 +349,7 @@ class MockRouteTracing : public RouteTracing {
 class MockRoute : public Route {
 public:
   MockRoute();
-  ~MockRoute();
+  ~MockRoute() override;
 
   // Router::Route
   MOCK_CONST_METHOD0(directResponseEntry, const DirectResponseEntry*());
@@ -366,7 +366,7 @@ class MockRoute : public Route {
 class MockConfig : public Config {
 public:
   MockConfig();
-  ~MockConfig();
+  ~MockConfig() override;
 
   // Router::Config
   MOCK_CONST_METHOD2(route, RouteConstSharedPtr(const Http::HeaderMap&, uint64_t random_value));
@@ -382,7 +382,7 @@ class MockConfig : public Config {
 class MockRouteConfigProviderManager : public RouteConfigProviderManager {
 public:
   MockRouteConfigProviderManager();
-  ~MockRouteConfigProviderManager();
+  ~MockRouteConfigProviderManager() override;
 
   MOCK_METHOD3(createRdsRouteConfigProvider,
                RouteConfigProviderPtr(
@@ -397,7 +397,7 @@ class MockRouteConfigProviderManager : public RouteConfigProviderManager {
 class MockScopedConfig : public ScopedConfig {
 public:
   MockScopedConfig();
-  ~MockScopedConfig();
+  ~MockScopedConfig() override;
 
   MOCK_CONST_METHOD1(getRouteConfig, ConfigConstSharedPtr(const Http::HeaderMap& headers));
 };
diff --git a/test/mocks/runtime/mocks.h b/test/mocks/runtime/mocks.h
index e67e34361958..3592a40200fa 100644
--- a/test/mocks/runtime/mocks.h
+++ b/test/mocks/runtime/mocks.h
@@ -15,7 +15,7 @@ namespace Runtime {
 class MockRandomGenerator : public RandomGenerator {
 public:
   MockRandomGenerator();
-  ~MockRandomGenerator();
+  ~MockRandomGenerator() override;
 
   MOCK_METHOD0(random, uint64_t());
   MOCK_METHOD0(uuid, std::string());
@@ -60,7 +60,7 @@ class MockSnapshot : public Snapshot {
 class MockLoader : public Loader {
 public:
   MockLoader();
-  ~MockLoader();
+  ~MockLoader() override;
 
   MOCK_METHOD1(initialize, void(Upstream::ClusterManager& cm));
   MOCK_METHOD0(snapshot, Snapshot&());
@@ -72,7 +72,7 @@ class MockLoader : public Loader {
 class MockOverrideLayer : public Snapshot::OverrideLayer {
 public:
   MockOverrideLayer();
-  ~MockOverrideLayer();
+  ~MockOverrideLayer() override;
 
   MOCK_CONST_METHOD0(name, const std::string&());
   MOCK_CONST_METHOD0(values, const Snapshot::EntryMap&());
diff --git a/test/mocks/secret/mocks.h b/test/mocks/secret/mocks.h
index 428f1ec28faa..2f3f2c5f073e 100644
--- a/test/mocks/secret/mocks.h
+++ b/test/mocks/secret/mocks.h
@@ -14,7 +14,7 @@ namespace Secret {
 class MockSecretManager : public SecretManager {
 public:
   MockSecretManager();
-  ~MockSecretManager();
+  ~MockSecretManager() override;
 
   MOCK_METHOD1(addStaticSecret, void(const envoy::api::v2::auth::Secret& secret));
   MOCK_CONST_METHOD1(findStaticTlsCertificateProvider,
@@ -42,7 +42,7 @@ class MockSecretManager : public SecretManager {
 class MockSecretCallbacks : public SecretCallbacks {
 public:
   MockSecretCallbacks();
-  ~MockSecretCallbacks();
+  ~MockSecretCallbacks() override;
   MOCK_METHOD0(onAddOrUpdateSecret, void());
 };
 
diff --git a/test/mocks/ssl/mocks.h b/test/mocks/ssl/mocks.h
index cd91a237327f..20621bd29ca4 100644
--- a/test/mocks/ssl/mocks.h
+++ b/test/mocks/ssl/mocks.h
@@ -20,7 +20,7 @@ namespace Ssl {
 class MockContextManager : public ContextManager {
 public:
   MockContextManager();
-  ~MockContextManager();
+  ~MockContextManager() override;
 
   MOCK_METHOD2(createSslClientContext,
                ClientContextSharedPtr(Stats::Scope& scope, const ClientContextConfig& config));
@@ -34,7 +34,7 @@ class MockContextManager : public ContextManager {
 class MockConnectionInfo : public ConnectionInfo {
 public:
   MockConnectionInfo();
-  ~MockConnectionInfo();
+  ~MockConnectionInfo() override;
 
   MOCK_CONST_METHOD0(peerCertificatePresented, bool());
   MOCK_CONST_METHOD0(uriSanLocalCertificate, std::vector<std::string>());
@@ -59,7 +59,7 @@ class MockConnectionInfo : public ConnectionInfo {
 class MockClientContext : public ClientContext {
 public:
   MockClientContext();
-  ~MockClientContext();
+  ~MockClientContext() override;
 
   MOCK_CONST_METHOD0(daysUntilFirstCertExpires, size_t());
   MOCK_CONST_METHOD0(getCaCertInformation, CertificateDetailsPtr());
@@ -69,7 +69,7 @@ class MockClientContext : public ClientContext {
 class MockClientContextConfig : public ClientContextConfig {
 public:
   MockClientContextConfig();
-  ~MockClientContextConfig();
+  ~MockClientContextConfig() override;
 
   MOCK_CONST_METHOD0(alpnProtocols, const std::string&());
   MOCK_CONST_METHOD0(cipherSuites, const std::string&());
@@ -91,7 +91,7 @@ class MockClientContextConfig : public ClientContextConfig {
 class MockServerContextConfig : public ServerContextConfig {
 public:
   MockServerContextConfig();
-  ~MockServerContextConfig();
+  ~MockServerContextConfig() override;
 
   MOCK_CONST_METHOD0(alpnProtocols, const std::string&());
   MOCK_CONST_METHOD0(cipherSuites, const std::string&());
diff --git a/test/mocks/stream_info/mocks.h b/test/mocks/stream_info/mocks.h
index 9332fec087ec..0fbd34222291 100644
--- a/test/mocks/stream_info/mocks.h
+++ b/test/mocks/stream_info/mocks.h
@@ -14,7 +14,7 @@ namespace StreamInfo {
 class MockStreamInfo : public StreamInfo {
 public:
   MockStreamInfo();
-  ~MockStreamInfo();
+  ~MockStreamInfo() override;
 
   // StreamInfo::StreamInfo
   MOCK_METHOD1(setResponseFlag, void(ResponseFlag response_flag));
diff --git a/test/mocks/tcp/mocks.h b/test/mocks/tcp/mocks.h
index 3f864ec3296d..5ac8b8ee6f80 100644
--- a/test/mocks/tcp/mocks.h
+++ b/test/mocks/tcp/mocks.h
@@ -18,7 +18,7 @@ namespace ConnectionPool {
 class MockCancellable : public Cancellable {
 public:
   MockCancellable();
-  ~MockCancellable();
+  ~MockCancellable() override;
 
   // Tcp::ConnectionPool::Cancellable
   MOCK_METHOD1(cancel, void(CancelPolicy cancel_policy));
@@ -27,7 +27,7 @@ class MockCancellable : public Cancellable {
 class MockUpstreamCallbacks : public UpstreamCallbacks {
 public:
   MockUpstreamCallbacks();
-  ~MockUpstreamCallbacks();
+  ~MockUpstreamCallbacks() override;
 
   // Tcp::ConnectionPool::UpstreamCallbacks
   MOCK_METHOD2(onUpstreamData, void(Buffer::Instance& data, bool end_stream));
@@ -39,7 +39,7 @@ class MockUpstreamCallbacks : public UpstreamCallbacks {
 class MockConnectionData : public ConnectionData {
 public:
   MockConnectionData();
-  ~MockConnectionData();
+  ~MockConnectionData() override;
 
   // Tcp::ConnectionPool::ConnectionData
   MOCK_METHOD0(connection, Network::ClientConnection&());
@@ -57,7 +57,7 @@ class MockConnectionData : public ConnectionData {
 class MockInstance : public Instance {
 public:
   MockInstance();
-  ~MockInstance();
+  ~MockInstance() override;
 
   // Tcp::ConnectionPool::Instance
   MOCK_METHOD1(addDrainedCallback, void(DrainedCb cb));
diff --git a/test/mocks/thread_local/mocks.h b/test/mocks/thread_local/mocks.h
index 24393722887a..3824deac4ac4 100644
--- a/test/mocks/thread_local/mocks.h
+++ b/test/mocks/thread_local/mocks.h
@@ -15,7 +15,7 @@ namespace ThreadLocal {
 class MockInstance : public Instance {
 public:
   MockInstance();
-  ~MockInstance();
+  ~MockInstance() override;
 
   MOCK_METHOD1(runOnAllThreads, void(Event::PostCb cb));
   MOCK_METHOD2(runOnAllThreads, void(Event::PostCb cb, Event::PostCb main_callback));
@@ -48,7 +48,7 @@ class MockInstance : public Instance {
       parent_.data_.resize(index_ + 1);
     }
 
-    ~SlotImpl() {
+    ~SlotImpl() override {
       // Do not actually clear slot data during shutdown. This mimics the production code.
       if (!parent_.shutdown_) {
         EXPECT_LT(index_, parent_.data_.size());
diff --git a/test/mocks/tracing/mocks.h b/test/mocks/tracing/mocks.h
index d62036fd8d07..22a694edfd9a 100644
--- a/test/mocks/tracing/mocks.h
+++ b/test/mocks/tracing/mocks.h
@@ -13,7 +13,7 @@ namespace Tracing {
 class MockConfig : public Config {
 public:
   MockConfig();
-  ~MockConfig();
+  ~MockConfig() override;
 
   MOCK_CONST_METHOD0(operationName, OperationName());
   MOCK_CONST_METHOD0(requestHeadersForTags, const std::vector<Http::LowerCaseString>&());
@@ -27,7 +27,7 @@ class MockConfig : public Config {
 class MockSpan : public Span {
 public:
   MockSpan();
-  ~MockSpan();
+  ~MockSpan() override;
 
   MOCK_METHOD1(setOperation, void(absl::string_view operation));
   MOCK_METHOD2(setTag, void(absl::string_view name, absl::string_view value));
@@ -48,7 +48,7 @@ class MockSpan : public Span {
 class MockHttpTracer : public HttpTracer {
 public:
   MockHttpTracer();
-  ~MockHttpTracer();
+  ~MockHttpTracer() override;
 
   SpanPtr startSpan(const Config& config, Http::HeaderMap& request_headers,
                     const StreamInfo::StreamInfo& stream_info,
@@ -64,7 +64,7 @@ class MockHttpTracer : public HttpTracer {
 class MockDriver : public Driver {
 public:
   MockDriver();
-  ~MockDriver();
+  ~MockDriver() override;
 
   SpanPtr startSpan(const Config& config, Http::HeaderMap& request_headers,
                     const std::string& operation_name, SystemTime start_time,
diff --git a/test/mocks/upstream/cluster_info.h b/test/mocks/upstream/cluster_info.h
index 46b318c3f36d..56df9fa4dcca 100644
--- a/test/mocks/upstream/cluster_info.h
+++ b/test/mocks/upstream/cluster_info.h
@@ -26,7 +26,7 @@ namespace Upstream {
 class MockLoadBalancerSubsetInfo : public LoadBalancerSubsetInfo {
 public:
   MockLoadBalancerSubsetInfo();
-  ~MockLoadBalancerSubsetInfo();
+  ~MockLoadBalancerSubsetInfo() override;
 
   // Upstream::LoadBalancerSubsetInfo
   MOCK_CONST_METHOD0(isEnabled, bool());
@@ -61,7 +61,7 @@ class MockClusterTypedMetadata : public Config::TypedMetadataImpl<ClusterTypedMe
 class MockClusterInfo : public ClusterInfo {
 public:
   MockClusterInfo();
-  ~MockClusterInfo();
+  ~MockClusterInfo() override;
 
   void resetResourceManager(uint64_t cx, uint64_t rq_pending, uint64_t rq, uint64_t rq_retry,
                             uint64_t conn_pool) {
@@ -135,7 +135,7 @@ class MockClusterInfo : public ClusterInfo {
 class MockIdleTimeEnabledClusterInfo : public MockClusterInfo {
 public:
   MockIdleTimeEnabledClusterInfo();
-  ~MockIdleTimeEnabledClusterInfo();
+  ~MockIdleTimeEnabledClusterInfo() override;
 };
 
 } // namespace Upstream
diff --git a/test/mocks/upstream/host.h b/test/mocks/upstream/host.h
index f4c43a2fd06b..095c67c1ae88 100644
--- a/test/mocks/upstream/host.h
+++ b/test/mocks/upstream/host.h
@@ -22,7 +22,7 @@ namespace Outlier {
 class MockDetectorHostMonitor : public DetectorHostMonitor {
 public:
   MockDetectorHostMonitor();
-  ~MockDetectorHostMonitor();
+  ~MockDetectorHostMonitor() override;
 
   MOCK_METHOD0(numEjections, uint32_t());
   MOCK_METHOD1(putHttpResponseCode, void(uint64_t code));
@@ -38,7 +38,7 @@ class MockDetectorHostMonitor : public DetectorHostMonitor {
 class MockEventLogger : public EventLogger {
 public:
   MockEventLogger();
-  ~MockEventLogger();
+  ~MockEventLogger() override;
 
   MOCK_METHOD4(logEject,
                void(const HostDescriptionConstSharedPtr& host, Detector& detector,
@@ -49,7 +49,7 @@ class MockEventLogger : public EventLogger {
 class MockDetector : public Detector {
 public:
   MockDetector();
-  ~MockDetector();
+  ~MockDetector() override;
 
   void runCallbacks(HostSharedPtr host) {
     for (const ChangeStateCb& cb : callbacks_) {
@@ -70,7 +70,7 @@ class MockDetector : public Detector {
 class MockHealthCheckHostMonitor : public HealthCheckHostMonitor {
 public:
   MockHealthCheckHostMonitor();
-  ~MockHealthCheckHostMonitor();
+  ~MockHealthCheckHostMonitor() override;
 
   MOCK_METHOD0(setUnhealthy, void());
 };
@@ -78,7 +78,7 @@ class MockHealthCheckHostMonitor : public HealthCheckHostMonitor {
 class MockHostDescription : public HostDescription {
 public:
   MockHostDescription();
-  ~MockHostDescription();
+  ~MockHostDescription() override;
 
   MOCK_CONST_METHOD0(address, Network::Address::InstanceConstSharedPtr());
   MOCK_CONST_METHOD0(healthCheckAddress, Network::Address::InstanceConstSharedPtr());
@@ -120,7 +120,7 @@ class MockHost : public Host {
   };
 
   MockHost();
-  ~MockHost();
+  ~MockHost() override;
 
   CreateConnectionData createConnection(Event::Dispatcher& dispatcher,
                                         const Network::ConnectionSocket::OptionsSharedPtr& options,
diff --git a/test/mocks/upstream/load_balancer_context.h b/test/mocks/upstream/load_balancer_context.h
index 495da74935a4..6d9e7046545c 100644
--- a/test/mocks/upstream/load_balancer_context.h
+++ b/test/mocks/upstream/load_balancer_context.h
@@ -8,7 +8,7 @@ namespace Upstream {
 class MockLoadBalancerContext : public LoadBalancerContext {
 public:
   MockLoadBalancerContext();
-  ~MockLoadBalancerContext();
+  ~MockLoadBalancerContext() override;
 
   MOCK_METHOD0(computeHashKey, absl::optional<uint64_t>());
   MOCK_METHOD0(metadataMatchCriteria, Router::MetadataMatchCriteria*());
diff --git a/test/mocks/upstream/mocks.h b/test/mocks/upstream/mocks.h
index e9b86baf2be6..f194bffceca0 100644
--- a/test/mocks/upstream/mocks.h
+++ b/test/mocks/upstream/mocks.h
@@ -38,7 +38,7 @@ class MockHostSet : public HostSet {
 public:
   MockHostSet(uint32_t priority = 0,
               uint32_t overprovisioning_factor = kDefaultOverProvisioningFactor);
-  ~MockHostSet();
+  ~MockHostSet() override;
 
   void runCallbacks(const HostVector added, const HostVector removed) {
     member_update_cb_helper_.runCallbacks(priority(), added, removed);
@@ -92,7 +92,7 @@ class MockHostSet : public HostSet {
 class MockPrioritySet : public PrioritySet {
 public:
   MockPrioritySet();
-  ~MockPrioritySet();
+  ~MockPrioritySet() override;
 
   HostSet& getHostSet(uint32_t priority);
   void runUpdateCallbacks(uint32_t priority, const HostVector& hosts_added,
@@ -125,10 +125,10 @@ class MockRetryPriority : public RetryPriority {
                     const DegradedLoad& degraded_priority_load)
       : priority_load_({healthy_priority_load, degraded_priority_load}) {}
   MockRetryPriority(const MockRetryPriority& other) : priority_load_(other.priority_load_) {}
-  ~MockRetryPriority();
+  ~MockRetryPriority() override;
 
   const HealthyAndDegradedLoad& determinePriorityLoad(const PrioritySet&,
-                                                      const HealthyAndDegradedLoad&) {
+                                                      const HealthyAndDegradedLoad&) override {
     return priority_load_;
   }
 
@@ -158,7 +158,7 @@ class MockRetryPriorityFactory : public RetryPriorityFactory {
 class MockCluster : public Cluster {
 public:
   MockCluster();
-  ~MockCluster();
+  ~MockCluster() override;
 
   // Upstream::Cluster
   MOCK_METHOD0(healthChecker, HealthChecker*());
@@ -182,7 +182,7 @@ class MockCluster : public Cluster {
 class MockClusterRealPrioritySet : public MockCluster {
 public:
   MockClusterRealPrioritySet();
-  ~MockClusterRealPrioritySet();
+  ~MockClusterRealPrioritySet() override;
 
   // Upstream::Cluster
   PrioritySetImpl& prioritySet() override { return priority_set_; }
@@ -195,7 +195,7 @@ class MockClusterRealPrioritySet : public MockCluster {
 class MockClusterMockPrioritySet : public MockCluster {
 public:
   MockClusterMockPrioritySet();
-  ~MockClusterMockPrioritySet();
+  ~MockClusterMockPrioritySet() override;
 
   // Upstream::Cluster
   MockPrioritySet& prioritySet() override { return priority_set_; }
@@ -207,7 +207,7 @@ class MockClusterMockPrioritySet : public MockCluster {
 class MockLoadBalancer : public LoadBalancer {
 public:
   MockLoadBalancer();
-  ~MockLoadBalancer();
+  ~MockLoadBalancer() override;
 
   // Upstream::LoadBalancer
   MOCK_METHOD1(chooseHost, HostConstSharedPtr(LoadBalancerContext* context));
@@ -218,7 +218,7 @@ class MockLoadBalancer : public LoadBalancer {
 class MockThreadAwareLoadBalancer : public ThreadAwareLoadBalancer {
 public:
   MockThreadAwareLoadBalancer();
-  ~MockThreadAwareLoadBalancer();
+  ~MockThreadAwareLoadBalancer() override;
 
   // Upstream::ThreadAwareLoadBalancer
   MOCK_METHOD0(factory, LoadBalancerFactorySharedPtr());
@@ -228,7 +228,7 @@ class MockThreadAwareLoadBalancer : public ThreadAwareLoadBalancer {
 class MockThreadLocalCluster : public ThreadLocalCluster {
 public:
   MockThreadLocalCluster();
-  ~MockThreadLocalCluster();
+  ~MockThreadLocalCluster() override;
 
   // Upstream::ThreadLocalCluster
   MOCK_METHOD0(prioritySet, const PrioritySet&());
@@ -242,7 +242,7 @@ class MockThreadLocalCluster : public ThreadLocalCluster {
 class MockClusterManagerFactory : public ClusterManagerFactory {
 public:
   MockClusterManagerFactory();
-  ~MockClusterManagerFactory();
+  ~MockClusterManagerFactory() override;
 
   Secret::MockSecretManager& secretManager() override { return secret_manager_; };
 
@@ -275,14 +275,14 @@ class MockClusterManagerFactory : public ClusterManagerFactory {
 class MockClusterUpdateCallbacksHandle : public ClusterUpdateCallbacksHandle {
 public:
   MockClusterUpdateCallbacksHandle();
-  ~MockClusterUpdateCallbacksHandle();
+  ~MockClusterUpdateCallbacksHandle() override;
 };
 
 class MockClusterManager : public ClusterManager {
 public:
   explicit MockClusterManager(TimeSource& time_source);
   MockClusterManager();
-  ~MockClusterManager();
+  ~MockClusterManager() override;
 
   ClusterUpdateCallbacksHandlePtr
   addThreadLocalClusterUpdateCallbacks(ClusterUpdateCallbacks& callbacks) override {
@@ -344,7 +344,7 @@ class MockClusterManager : public ClusterManager {
 class MockHealthChecker : public HealthChecker {
 public:
   MockHealthChecker();
-  ~MockHealthChecker();
+  ~MockHealthChecker() override;
 
   MOCK_METHOD1(addHostCheckCompleteCb, void(HostStatusCb callback));
   MOCK_METHOD0(start, void());
@@ -377,7 +377,7 @@ class MockHealthCheckEventLogger : public HealthCheckEventLogger {
 class MockCdsApi : public CdsApi {
 public:
   MockCdsApi();
-  ~MockCdsApi();
+  ~MockCdsApi() override;
 
   MOCK_METHOD0(initialize, void());
   MOCK_METHOD1(setInitializedCb, void(std::function<void()> callback));
@@ -389,7 +389,7 @@ class MockCdsApi : public CdsApi {
 class MockClusterUpdateCallbacks : public ClusterUpdateCallbacks {
 public:
   MockClusterUpdateCallbacks();
-  ~MockClusterUpdateCallbacks();
+  ~MockClusterUpdateCallbacks() override;
 
   MOCK_METHOD1(onClusterAddOrUpdate, void(ThreadLocalCluster& cluster));
   MOCK_METHOD1(onClusterRemoval, void(const std::string& cluster_name));
@@ -398,7 +398,7 @@ class MockClusterUpdateCallbacks : public ClusterUpdateCallbacks {
 class MockClusterInfoFactory : public ClusterInfoFactory, Logger::Loggable<Logger::Id::upstream> {
 public:
   MockClusterInfoFactory();
-  ~MockClusterInfoFactory();
+  ~MockClusterInfoFactory() override;
 
   MOCK_METHOD1(createClusterInfo, ClusterInfoConstSharedPtr(const CreateClusterInfoParams&));
 };
@@ -406,7 +406,7 @@ class MockClusterInfoFactory : public ClusterInfoFactory, Logger::Loggable<Logge
 class MockRetryHostPredicate : public RetryHostPredicate {
 public:
   MockRetryHostPredicate();
-  ~MockRetryHostPredicate();
+  ~MockRetryHostPredicate() override;
 
   MOCK_METHOD1(shouldSelectAnotherHost, bool(const Host& candidate_host));
   MOCK_METHOD1(onHostAttempted, void(HostDescriptionConstSharedPtr));
diff --git a/test/server/filter_chain_benchmark_test.cc b/test/server/filter_chain_benchmark_test.cc
index 5070cc1271ae..3cc2788df84f 100644
--- a/test/server/filter_chain_benchmark_test.cc
+++ b/test/server/filter_chain_benchmark_test.cc
@@ -149,7 +149,7 @@ const char YamlSingleDstPortBottom[] = R"EOF(
 
 class FilterChainBenchmarkFixture : public benchmark::Fixture {
 public:
-  void SetUp(const ::benchmark::State& state) {
+  void SetUp(const ::benchmark::State& state) override {
     int64_t input_size = state.range(0);
     std::vector<std::string> port_chains;
     for (int i = 0; i < input_size; i++) {
diff --git a/test/server/guarddog_impl_test.cc b/test/server/guarddog_impl_test.cc
index 77b3397ffd59..e4f5d35f8e2c 100644
--- a/test/server/guarddog_impl_test.cc
+++ b/test/server/guarddog_impl_test.cc
@@ -30,12 +30,12 @@ namespace {
 class DebugTestInterlock : public GuardDogImpl::TestInterlockHook {
 public:
   // GuardDogImpl::TestInterlockHook
-  virtual void signalFromImpl(MonotonicTime time) {
+  void signalFromImpl(MonotonicTime time) override {
     impl_reached_ = time;
     impl_.notifyAll();
   }
 
-  virtual void waitFromTest(Thread::MutexBasicLockable& mutex, MonotonicTime time)
+  void waitFromTest(Thread::MutexBasicLockable& mutex, MonotonicTime time) override
       EXCLUSIVE_LOCKS_REQUIRED(mutex) {
     while (impl_reached_ < time) {
       impl_.wait(mutex);
diff --git a/test/server/http/config_tracker_impl_test.cc b/test/server/http/config_tracker_impl_test.cc
index d085e2c962af..60d4633f08a7 100644
--- a/test/server/http/config_tracker_impl_test.cc
+++ b/test/server/http/config_tracker_impl_test.cc
@@ -21,7 +21,7 @@ class ConfigTrackerImplTest : public testing::Test {
 
   ProtobufTypes::MessagePtr test_msg() { return std::make_unique<ProtobufWkt::Any>(); }
 
-  virtual ~ConfigTrackerImplTest() = default;
+  ~ConfigTrackerImplTest() override = default;
 
   ConfigTrackerImpl tracker;
   const std::map<std::string, ConfigTracker::Cb>& cbs_map;
diff --git a/test/test_common/logging.h b/test/test_common/logging.h
index c7e1fed70c9a..62fe9f6d7d53 100644
--- a/test/test_common/logging.h
+++ b/test/test_common/logging.h
@@ -49,7 +49,7 @@ class LogLevelSetter {
 class LogRecordingSink : public Logger::SinkDelegate {
 public:
   explicit LogRecordingSink(Logger::DelegatingLogSinkPtr log_sink);
-  virtual ~LogRecordingSink();
+  ~LogRecordingSink() override;
 
   // Logger::SinkDelegate
   void log(absl::string_view msg) override;
diff --git a/test/test_common/simulated_time_system.cc b/test/test_common/simulated_time_system.cc
index 1e700f650832..c4801ae68bda 100644
--- a/test/test_common/simulated_time_system.cc
+++ b/test/test_common/simulated_time_system.cc
@@ -55,7 +55,7 @@ class SimulatedTimeSystemHelper::Alarm : public Timer {
         time_system_(time_system), index_(time_system.nextIndex()), armed_(false), pending_(false) {
   }
 
-  virtual ~Alarm();
+  ~Alarm() override;
 
   // Timer
   void disableTimer() override;
diff --git a/test/test_common/test_time_system.h b/test/test_common/test_time_system.h
index bd3c184648ad..4d2ef8196642 100644
--- a/test/test_common/test_time_system.h
+++ b/test/test_common/test_time_system.h
@@ -15,7 +15,7 @@ class TestTimeSystem;
 // Adds sleep() and waitFor() interfaces to Event::TimeSystem.
 class TestTimeSystem : public Event::TimeSystem {
 public:
-  virtual ~TestTimeSystem() = default;
+  ~TestTimeSystem() override = default;
 
   /**
    * Advances time forward by the specified duration, running any timers