diff --git a/.changelog/21362.txt b/.changelog/21362.txt
new file mode 100644
index 00000000000..6693805974a
--- /dev/null
+++ b/.changelog/21362.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+resource/aws_codedeploy_deployment_group: Correctly update `deployment_group_name` argument
+```
diff --git a/internal/service/codedeploy/deployment_group.go b/internal/service/codedeploy/deployment_group.go
index a25f364ea50..0a4402cebc3 100644
--- a/internal/service/codedeploy/deployment_group.go
+++ b/internal/service/codedeploy/deployment_group.go
@@ -701,18 +701,19 @@ func resourceDeploymentGroupUpdate(d *schema.ResourceData, meta interface{}) err
 	if d.HasChangesExcept("tags", "tags_all") {
 		// required fields
 		applicationName := d.Get("app_name").(string)
-		deploymentGroupName := d.Get("deployment_group_name").(string)
 		serviceRoleArn := d.Get("service_role_arn").(string)
 
 		input := codedeploy.UpdateDeploymentGroupInput{
-			ApplicationName:            aws.String(applicationName),
-			CurrentDeploymentGroupName: aws.String(deploymentGroupName),
-			ServiceRoleArn:             aws.String(serviceRoleArn),
+			ApplicationName: aws.String(applicationName),
+			ServiceRoleArn:  aws.String(serviceRoleArn),
 		}
 
 		if d.HasChange("deployment_group_name") {
-			_, n := d.GetChange("deployment_group_name")
+			o, n := d.GetChange("deployment_group_name")
+			input.CurrentDeploymentGroupName = aws.String(o.(string))
 			input.NewDeploymentGroupName = aws.String(n.(string))
+		} else {
+			input.CurrentDeploymentGroupName = aws.String(d.Get("deployment_group_name").(string))
 		}
 
 		if d.HasChange("deployment_style") {
@@ -805,7 +806,7 @@ func resourceDeploymentGroupUpdate(d *schema.ResourceData, meta interface{}) err
 			_, err = conn.UpdateDeploymentGroup(&input)
 		}
 		if err != nil {
-			return fmt.Errorf("Error updating CodeDeploy deployment group: %w", err)
+			return fmt.Errorf("error updating CodeDeploy deployment group (%s): %w", d.Id(), err)
 		}
 	}