diff --git a/browser/net/brave_network_delegate_browsertest.cc b/browser/net/brave_network_delegate_browsertest.cc
index cf71e2121e2e..c35d6c1096a8 100644
--- a/browser/net/brave_network_delegate_browsertest.cc
+++ b/browser/net/brave_network_delegate_browsertest.cc
@@ -61,6 +61,9 @@ class BraveNetworkDelegateBrowserTest : public InProcessBrowserTest {
 
     third_party_cookie_url_ =
         embedded_test_server()->GetURL("b.com", "/set-cookie?name=Good");
+    subdomain_first_party_cookie_url_ =
+        embedded_test_server()->GetURL("subdomain.a.com",
+                                       "/set-cookie?name=Good");
     google_oauth_cookie_url_ =
         https_server_.GetURL("accounts.google.com", "/set-cookie?oauth=true");
 
@@ -158,6 +161,7 @@ class BraveNetworkDelegateBrowserTest : public InProcessBrowserTest {
   GURL cookie_iframe_url_;
   GURL https_cookie_iframe_url_;
   GURL third_party_cookie_url_;
+  GURL subdomain_first_party_cookie_url_;
   GURL google_oauth_cookie_url_;
   GURL wordpress_top_url_;
   GURL wordpress_frame_url_;
@@ -255,7 +259,12 @@ IN_PROC_BROWSER_TEST_F(BraveNetworkDelegateBrowserTest,
   NavigateFrameTo(third_party_cookie_url_);
 
   ExpectCookiesOnHost(top_level_page_url_, "name=Good");
-  ExpectCookiesOnHost(GURL(third_party_cookie_url_.host()), "");
+  ExpectCookiesOnHost(third_party_cookie_url_, "");
+
+  NavigateFrameTo(subdomain_first_party_cookie_url_);
+
+  ExpectCookiesOnHost(top_level_page_url_, "name=Good");
+  ExpectCookiesOnHost(subdomain_first_party_cookie_url_, "name=Good");
 }
 
 IN_PROC_BROWSER_TEST_F(BraveNetworkDelegateBrowserTest,
@@ -328,6 +337,11 @@ IN_PROC_BROWSER_TEST_F(BraveNetworkDelegateBrowserTest,
 
   ExpectCookiesOnHost(top_level_page_url_, "name=Good");
   ExpectCookiesOnHost(GURL("http://b.com"), "");
+
+  NavigateFrameTo(subdomain_first_party_cookie_url_);
+
+  ExpectCookiesOnHost(top_level_page_url_, "name=Good");
+  ExpectCookiesOnHost(subdomain_first_party_cookie_url_, "name=Good");
 }
 
 IN_PROC_BROWSER_TEST_F(BraveNetworkDelegateBrowserTest,
diff --git a/components/content_settings/core/browser/brave_content_settings_pref_provider.cc b/components/content_settings/core/browser/brave_content_settings_pref_provider.cc
index 6c5bb20f83d9..e963c07e9233 100644
--- a/components/content_settings/core/browser/brave_content_settings_pref_provider.cc
+++ b/components/content_settings/core/browser/brave_content_settings_pref_provider.cc
@@ -31,7 +31,12 @@ Rule CloneRule(const Rule& rule, bool reverse_patterns = false) {
   auto secondary_pattern = rule.secondary_pattern;
   if (secondary_pattern ==
       ContentSettingsPattern::FromString("https://firstParty/*")) {
-    secondary_pattern = rule.primary_pattern;
+    if (!rule.primary_pattern.MatchesAllHosts()) {
+      secondary_pattern = ContentSettingsPattern::FromString(
+          "*://[*.]" + rule.primary_pattern.GetHost() + "/*");
+    } else {
+      secondary_pattern = rule.primary_pattern;
+    }
   }
 
   // brave plugin rules incorrectly use the embedded url as the primary