diff --git a/.gitignore b/.gitignore
index 43e8b06a15..0fc9f90295 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,6 +18,7 @@ dist
 tools-stamp
 buf-stamp
 artifacts
+simapp/simd/simd
 
 # Go
 go.work
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9be3419529..0cc91d2382 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -53,6 +53,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Improvements
 
+* (client/keys) [#18703](https://github.com/cosmos/cosmos-sdk/pull/18703) Improve `<appd> keys add` and `<appd> keys show` by checking whether there are duplicate keys in the multisig case.
 * (x/gov) [#18707](https://github.com/cosmos/cosmos-sdk/pull/18707) Improve genesis validation. 
 * (x/bank) [#18636](https://github.com/cosmos/cosmos-sdk/pull/18636) `SendCoinsFromModuleToAccount`, `SendCoinsFromModuleToModule`, `SendCoinsFromAccountToModule`, `DelegateCoinsFromAccountToModule`, `UndelegateCoinsFromModuleToAccount`, `MintCoins` and `BurnCoins` methods now returns an error instead of panicking if any module accounts does not exist or unauthorized.
 * (x/distribution) [#18636](https://github.com/cosmos/cosmos-sdk/pull/18636) `CalculateDelegationRewards` and `DelegationTotalRewards` methods no longer panics on any sanity checks and instead returns appropriate errors.
diff --git a/client/keys/add.go b/client/keys/add.go
index 527209c918..a30a2d865a 100644
--- a/client/keys/add.go
+++ b/client/keys/add.go
@@ -164,8 +164,14 @@ func runAddCmd(ctx client.Context, cmd *cobra.Command, args []string, inBuf *buf
 				return err
 			}
 
-			for i, keyname := range multisigKeys {
-				k, err := kb.Key(keyname)
+			seenKeys := make(map[string]struct{})
+			for i, keyName := range multisigKeys {
+				if _, ok := seenKeys[keyName]; ok {
+					return fmt.Errorf("duplicate multisig keys: %s", keyName)
+				}
+				seenKeys[keyName] = struct{}{}
+
+				k, err := kb.Key(keyName)
 				if err != nil {
 					return err
 				}
diff --git a/client/keys/add_test.go b/client/keys/add_test.go
index 84b81833bb..53ce3af279 100644
--- a/client/keys/add_test.go
+++ b/client/keys/add_test.go
@@ -127,6 +127,77 @@ func Test_runAddCmdBasic(t *testing.T) {
 	require.Error(t, cmd.ExecuteContext(ctx))
 }
 
+func Test_runAddCmdMultisigDupKeys(t *testing.T) {
+	cmd := AddKeyCommand()
+	cmd.Flags().AddFlagSet(Commands().PersistentFlags())
+
+	mockIn := testutil.ApplyMockIODiscardOutErr(cmd)
+	kbHome := t.TempDir()
+
+	cdc := moduletestutil.MakeTestEncodingConfig().Codec
+	kb, err := keyring.New(sdk.KeyringServiceName(), keyring.BackendTest, kbHome, mockIn, cdc)
+	require.NoError(t, err)
+
+	clientCtx := client.Context{}.
+		WithKeyringDir(kbHome).
+		WithInput(mockIn).
+		WithCodec(cdc).
+		WithAddressCodec(addresscodec.NewBech32Codec("cosmos")).
+		WithValidatorAddressCodec(addresscodec.NewBech32Codec("cosmosvaloper")).
+		WithConsensusAddressCodec(addresscodec.NewBech32Codec("cosmosvalcons"))
+
+	ctx := context.WithValue(context.Background(), client.ClientContextKey, &clientCtx)
+
+	t.Cleanup(func() {
+		_ = kb.Delete("keyname1")
+		_ = kb.Delete("keyname2")
+		_ = kb.Delete("multisigname")
+	})
+
+	cmd.SetArgs([]string{
+		"keyname1",
+		fmt.Sprintf("--%s=%s", flags.FlagKeyringDir, kbHome),
+		fmt.Sprintf("--%s=%s", flags.FlagOutput, flags.OutputFormatText),
+		fmt.Sprintf("--%s=%s", flags.FlagKeyType, hd.Secp256k1Type),
+		fmt.Sprintf("--%s=%s", flags.FlagKeyringBackend, keyring.BackendTest),
+	})
+	require.NoError(t, cmd.ExecuteContext(ctx))
+
+	cmd.SetArgs([]string{
+		"keyname2",
+		fmt.Sprintf("--%s=%s", flags.FlagKeyringDir, kbHome),
+		fmt.Sprintf("--%s=%s", flags.FlagOutput, flags.OutputFormatText),
+		fmt.Sprintf("--%s=%s", flags.FlagKeyType, hd.Secp256k1Type),
+		fmt.Sprintf("--%s=%s", flags.FlagKeyringBackend, keyring.BackendTest),
+	})
+	require.NoError(t, cmd.ExecuteContext(ctx))
+
+	cmd.SetArgs([]string{
+		"multisigname",
+		fmt.Sprintf("--%s=%s", flags.FlagKeyringDir, kbHome),
+		fmt.Sprintf("--%s=%s", flags.FlagOutput, flags.OutputFormatText),
+		fmt.Sprintf("--%s=%s", flags.FlagKeyType, hd.Secp256k1Type),
+		fmt.Sprintf("--%s=%s", flags.FlagKeyringBackend, keyring.BackendTest),
+		fmt.Sprintf("--%s=%s", flagMultisig, "keyname1,keyname2"),
+		fmt.Sprintf("--%s=%s", flagMultiSigThreshold, "2"),
+	})
+	require.NoError(t, cmd.ExecuteContext(ctx))
+
+	cmd.SetArgs([]string{
+		"multisigname",
+		fmt.Sprintf("--%s=%s", flags.FlagKeyringDir, kbHome),
+		fmt.Sprintf("--%s=%s", flags.FlagOutput, flags.OutputFormatText),
+		fmt.Sprintf("--%s=%s", flags.FlagKeyType, hd.Secp256k1Type),
+		fmt.Sprintf("--%s=%s", flags.FlagKeyringBackend, keyring.BackendTest),
+		fmt.Sprintf("--%s=%s", flagMultisig, "keyname1,keyname1"),
+		fmt.Sprintf("--%s=%s", flagMultiSigThreshold, "2"),
+	})
+	mockIn.Reset("y\n")
+	require.Error(t, cmd.ExecuteContext(ctx))
+	mockIn.Reset("y\n")
+	require.EqualError(t, cmd.ExecuteContext(ctx), "duplicate multisig keys: keyname1")
+}
+
 func Test_runAddCmdDryRun(t *testing.T) {
 	pubkey1 := `{"@type":"/cosmos.crypto.secp256k1.PubKey","key":"AtObiFVE4s+9+RX5SP8TN9r2mxpoaT4eGj9CJfK7VRzN"}`
 	pubkey2 := `{"@type":"/cosmos.crypto.secp256k1.PubKey","key":"A/se1vkqgdQ7VJQCM4mxN+L+ciGhnnJ4XYsQCRBMrdRi"}`
diff --git a/client/keys/show.go b/client/keys/show.go
index 582e6ec9c1..afda1b5fd6 100644
--- a/client/keys/show.go
+++ b/client/keys/show.go
@@ -71,11 +71,20 @@ func runShowCmd(cmd *cobra.Command, args []string) (err error) {
 		}
 	} else {
 		pks := make([]cryptotypes.PubKey, len(args))
-		for i, keyref := range args {
-			k, err := fetchKey(clientCtx.Keyring, keyref, clientCtx.AddressCodec)
-			if err != nil {
-				return fmt.Errorf("%s is not a valid name or address: %w", keyref, err)
+		seenKeys := make(map[string]struct{})
+		for i, keyRef := range args {
+			if _, ok := seenKeys[keyRef]; ok {
+				// we just show warning message instead of return error in case someone relies on this behavior.
+				cmd.PrintErrf("WARNING: duplicate keys found: %s.\n\n", keyRef)
+			} else {
+				seenKeys[keyRef] = struct{}{}
 			}
+
+			k, err := fetchKey(clientCtx.Keyring, keyRef, clientCtx.AddressCodec)
+			if err != nil {
+				return fmt.Errorf("%s is not a valid name or address: %w", keyRef, err)
+			}
+
 			key, err := k.GetPubKey()
 			if err != nil {
 				return err
diff --git a/client/keys/show_test.go b/client/keys/show_test.go
index 6763855259..5d7f9c0332 100644
--- a/client/keys/show_test.go
+++ b/client/keys/show_test.go
@@ -134,6 +134,18 @@ func Test_runShowCmd(t *testing.T) {
 	})
 	require.EqualError(t, cmd.ExecuteContext(ctx), "threshold must be a positive integer")
 
+	// Now try multisig key duplicate
+	_, mockOut := testutil.ApplyMockIO(cmd)
+	cmd.SetArgs([]string{
+		fakeKeyName1, fakeKeyName1,
+		fmt.Sprintf("--%s=%s", flags.FlagKeyringDir, kbHome),
+		fmt.Sprintf("--%s=%s", FlagBechPrefix, sdk.PrefixAccount),
+		fmt.Sprintf("--%s=2", flagMultiSigThreshold),
+		fmt.Sprintf("--%s=%s", flags.FlagKeyringBackend, keyring.BackendTest),
+	})
+	require.NoError(t, cmd.ExecuteContext(ctx))
+	require.Contains(t, mockOut.String(), fmt.Sprintf("WARNING: duplicate keys found: %s", fakeKeyName1))
+
 	cmd.SetArgs([]string{
 		fakeKeyName1, fakeKeyName2,
 		fmt.Sprintf("--%s=%s", flags.FlagKeyringDir, kbHome),