diff --git a/.changelog/38168.txt b/.changelog/38168.txt
new file mode 100644
index 00000000000..79ed38b1b39
--- /dev/null
+++ b/.changelog/38168.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+data-source/aws_cognito_user_pool_client: Fix `InvalidParameterException: 2 validation errors detected`  errors on Read
+```
diff --git a/internal/service/cognitoidp/user_pool_client_data_source.go b/internal/service/cognitoidp/user_pool_client_data_source.go
index 434d252c584..9d538f4eb9b 100644
--- a/internal/service/cognitoidp/user_pool_client_data_source.go
+++ b/internal/service/cognitoidp/user_pool_client_data_source.go
@@ -187,7 +187,7 @@ func dataSourceUserPoolClientRead(ctx context.Context, d *schema.ResourceData, m
 	conn := meta.(*conns.AWSClient).CognitoIDPClient(ctx)
 
 	clientID := d.Get(names.AttrClientID).(string)
-	userPoolClient, err := findUserPoolClientByTwoPartKey(ctx, conn, d.Get(names.AttrUserPoolID).(string), d.Id())
+	userPoolClient, err := findUserPoolClientByTwoPartKey(ctx, conn, d.Get(names.AttrUserPoolID).(string), clientID)
 
 	if err != nil {
 		return sdkdiag.AppendErrorf(diags, "reading Cognito User Pool Client (%s): %s", clientID, err)
diff --git a/internal/service/cognitoidp/user_pool_client_data_source_test.go b/internal/service/cognitoidp/user_pool_client_data_source_test.go
index cf9b3f92ca3..e3c8b80694b 100644
--- a/internal/service/cognitoidp/user_pool_client_data_source_test.go
+++ b/internal/service/cognitoidp/user_pool_client_data_source_test.go
@@ -6,6 +6,7 @@ package cognitoidp_test
 import (
 	"testing"
 
+	awstypes "github.com/aws/aws-sdk-go-v2/service/cognitoidentityprovider/types"
 	sdkacctest "github.com/hashicorp/terraform-plugin-testing/helper/acctest"
 	"github.com/hashicorp/terraform-plugin-testing/helper/resource"
 	"github.com/hashicorp/terraform-provider-aws/internal/acctest"
@@ -14,6 +15,7 @@ import (
 
 func TestAccCognitoIDPUserPoolClientDataSource_basic(t *testing.T) {
 	ctx := acctest.Context(t)
+	var client awstypes.UserPoolClientType
 	rName := sdkacctest.RandomWithPrefix(acctest.ResourcePrefix)
 	resourceName := "data.aws_cognito_user_pool_client.test"
 
@@ -25,6 +27,7 @@ func TestAccCognitoIDPUserPoolClientDataSource_basic(t *testing.T) {
 			{
 				Config: testAccUserPoolClientDataSourceConfig_basic(rName),
 				Check: resource.ComposeAggregateTestCheckFunc(
+					testAccCheckUserPoolClientExists(ctx, resourceName, &client),
 					resource.TestCheckResourceAttr(resourceName, names.AttrName, rName),
 					resource.TestCheckResourceAttr(resourceName, "explicit_auth_flows.#", acctest.Ct1),
 					resource.TestCheckTypeSetElemAttr(resourceName, "explicit_auth_flows.*", "ADMIN_NO_SRP_AUTH"),