diff --git a/packages/@aws-cdk/core/lib/stack.ts b/packages/@aws-cdk/core/lib/stack.ts
index 4960991a08b26..91410813fa176 100644
--- a/packages/@aws-cdk/core/lib/stack.ts
+++ b/packages/@aws-cdk/core/lib/stack.ts
@@ -371,6 +371,9 @@ export class Stack extends CoreConstruct implements ITaggable {
     }
 
     this._stackName = props.stackName ?? this.generateStackName();
+    if (this._stackName.length > 128) {
+      throw new Error(`Stack name must be <= 128 characters. Stack name: '${this._stackName}'`);
+    }
     this.tags = new TagManager(TagType.KEY_VALUE, 'aws:cdk:stack', props.tags);
 
     if (!VALID_STACK_NAME_REGEX.test(this.stackName)) {
diff --git a/packages/@aws-cdk/core/test/stack.test.ts b/packages/@aws-cdk/core/test/stack.test.ts
index e41796bccb624..d55352601503b 100644
--- a/packages/@aws-cdk/core/test/stack.test.ts
+++ b/packages/@aws-cdk/core/test/stack.test.ts
@@ -20,6 +20,19 @@ describe('stack', () => {
     expect(toCloudFormation(stack)).toEqual({ });
   });
 
+  test('stack name cannot exceed 128 characters', () => {
+    // GIVEN
+    const app = new App({});
+    const reallyLongStackName = 'LookAtMyReallyLongStackNameThisStackNameIsLongerThan128CharactersThatIsNutsIDontThinkThereIsEnoughAWSAvailableToLetEveryoneHaveStackNamesThisLong';
+
+    // THEN
+    expect(() => {
+      new Stack(app, 'MyStack', {
+        stackName: reallyLongStackName,
+      });
+    }).toThrow(`Stack name must be <= 128 characters. Stack name: '${reallyLongStackName}'`);
+  });
+
   test('stack objects have some template-level propeties, such as Description, Version, Transform', () => {
     const stack = new Stack();
     stack.templateOptions.templateFormatVersion = 'MyTemplateVersion';
diff --git a/packages/@aws-cdk/pipelines/test/codepipeline/codebuild-step.test.ts b/packages/@aws-cdk/pipelines/test/codepipeline/codebuild-step.test.ts
index 5b9538a5a4d00..a48b41ce1d6c6 100644
--- a/packages/@aws-cdk/pipelines/test/codepipeline/codebuild-step.test.ts
+++ b/packages/@aws-cdk/pipelines/test/codepipeline/codebuild-step.test.ts
@@ -125,8 +125,8 @@ test('timeout from defaults can be overridden', () => {
 test('envFromOutputs works even with very long stage and stack names', () => {
   const pipeline = new ModernTestGitHubNpmPipeline(pipelineStack, 'Cdk');
 
-  const myApp = new AppWithOutput(app, 'Alpha'.repeat(20), {
-    stackId: 'Stack'.repeat(20),
+  const myApp = new AppWithOutput(app, 'Alpha'.repeat(10), {
+    stackId: 'Stack'.repeat(10),
   });
 
   pipeline.addStage(myApp, {