diff --git a/CHANGELOG.md b/CHANGELOG.md
index 25c2a1a9e66..46dd4eb05a4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -39,6 +39,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Bug Fixes
 
+* (crypto) [#20027](https://github.com/cosmos/cosmos-sdk/pull/20027) secp256r1 keys now implement gogoproto's customtype interface.
 * (x/gov) [#19725](https://github.com/cosmos/cosmos-sdk/pull/19725) Fetch a failed proposal tally from proposal.FinalTallyResult in the gprc query.
 * (crypto) [#19691](https://github.com/cosmos/cosmos-sdk/pull/19746) Fix tx sign doesn't throw an error when incorrect Ledger is used.
 
diff --git a/crypto/keys/secp256r1/privkey.go b/crypto/keys/secp256r1/privkey.go
index c6702111c73..a0ae1b069bc 100644
--- a/crypto/keys/secp256r1/privkey.go
+++ b/crypto/keys/secp256r1/privkey.go
@@ -1,10 +1,14 @@
 package secp256r1
 
 import (
+	"encoding/base64"
+
 	"github.com/cosmos/cosmos-sdk/crypto/keys/internal/ecdsa"
 	cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
 )
 
+var _ customProtobufType = (*ecdsaSK)(nil)
+
 // GenPrivKey generates a new secp256r1 private key. It uses operating system randomness.
 func GenPrivKey() (*PrivKey, error) {
 	key, err := ecdsa.GenPrivKey(secp256r1)
@@ -52,6 +56,27 @@ type ecdsaSK struct {
 	ecdsa.PrivKey
 }
 
+// Marshal implements customProtobufType.
+func (sk ecdsaSK) Marshal() ([]byte, error) {
+	return sk.PrivKey.Bytes(), nil
+}
+
+// MarshalJSON implements customProtobufType.
+func (sk ecdsaSK) MarshalJSON() ([]byte, error) {
+	b64 := base64.StdEncoding.EncodeToString(sk.PrivKey.Bytes())
+	return []byte(b64), nil
+}
+
+// UnmarshalJSON implements customProtobufType.
+func (sk *ecdsaSK) UnmarshalJSON(data []byte) error {
+	bz, err := base64.StdEncoding.DecodeString(string(data))
+	if err != nil {
+		return err
+	}
+
+	return sk.PrivKey.Unmarshal(bz, secp256r1, fieldSize)
+}
+
 // Size implements proto.Marshaler interface
 func (sk *ecdsaSK) Size() int {
 	if sk == nil {
diff --git a/crypto/keys/secp256r1/privkey_internal_test.go b/crypto/keys/secp256r1/privkey_internal_test.go
index 771582d6a41..11b234191fc 100644
--- a/crypto/keys/secp256r1/privkey_internal_test.go
+++ b/crypto/keys/secp256r1/privkey_internal_test.go
@@ -113,3 +113,14 @@ func (suite *SKSuite) TestSize() {
 	var nilPk *ecdsaSK
 	require.Equal(0, nilPk.Size(), "nil value must have zero size")
 }
+
+func (suite *SKSuite) TestJson() {
+	require := suite.Require()
+	asd := suite.sk.(*PrivKey)
+	bz, err := asd.Secret.MarshalJSON()
+	require.NoError(err)
+
+	sk := &ecdsaSK{}
+	require.NoError(sk.UnmarshalJSON(bz))
+	require.Equal(suite.sk.(*PrivKey).Secret, sk)
+}
diff --git a/crypto/keys/secp256r1/pubkey.go b/crypto/keys/secp256r1/pubkey.go
index bf79c33cb9c..9574994bac8 100644
--- a/crypto/keys/secp256r1/pubkey.go
+++ b/crypto/keys/secp256r1/pubkey.go
@@ -1,6 +1,8 @@
 package secp256r1
 
 import (
+	"encoding/base64"
+
 	tmcrypto "github.com/cometbft/cometbft/crypto"
 	"github.com/cosmos/gogoproto/proto"
 
@@ -8,6 +10,20 @@ import (
 	cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
 )
 
+// customProtobufType is here to make sure that ecdsaPK and ecdsaSK implement the
+// gogoproto customtype interface.
+type customProtobufType interface {
+	Marshal() ([]byte, error)
+	MarshalTo(data []byte) (n int, err error)
+	Unmarshal(data []byte) error
+	Size() int
+
+	MarshalJSON() ([]byte, error)
+	UnmarshalJSON(data []byte) error
+}
+
+var _ customProtobufType = (*ecdsaPK)(nil)
+
 // String implements proto.Message interface.
 func (m *PubKey) String() string {
 	return m.Key.String(name)
@@ -49,6 +65,27 @@ type ecdsaPK struct {
 	ecdsa.PubKey
 }
 
+// Marshal implements customProtobufType.
+func (pk ecdsaPK) Marshal() ([]byte, error) {
+	return pk.PubKey.Bytes(), nil
+}
+
+// MarshalJSON implements customProtobufType.
+func (pk ecdsaPK) MarshalJSON() ([]byte, error) {
+	b64 := base64.StdEncoding.EncodeToString(pk.PubKey.Bytes())
+	return []byte(b64), nil
+}
+
+// UnmarshalJSON implements customProtobufType.
+func (pk *ecdsaPK) UnmarshalJSON(data []byte) error {
+	bz, err := base64.StdEncoding.DecodeString(string(data))
+	if err != nil {
+		return err
+	}
+
+	return pk.PubKey.Unmarshal(bz, secp256r1, pubKeySize)
+}
+
 // Size implements proto.Marshaler interface
 func (pk *ecdsaPK) Size() int {
 	if pk == nil {
diff --git a/crypto/keys/secp256r1/pubkey_internal_test.go b/crypto/keys/secp256r1/pubkey_internal_test.go
index eecbbb24d7d..f29eb15853d 100644
--- a/crypto/keys/secp256r1/pubkey_internal_test.go
+++ b/crypto/keys/secp256r1/pubkey_internal_test.go
@@ -126,3 +126,14 @@ func (suite *PKSuite) TestSize() {
 	var nilPk *ecdsaPK
 	require.Equal(0, nilPk.Size(), "nil value must have zero size")
 }
+
+func (suite *PKSuite) TestJson() {
+	require := suite.Require()
+
+	bz, err := suite.pk.Key.MarshalJSON()
+	require.NoError(err)
+
+	pk := &ecdsaPK{}
+	require.NoError(pk.UnmarshalJSON(bz))
+	require.Equal(suite.pk.Key, pk)
+}