diff --git a/packages/frontend-plugin-api/src/extensions/ThemeBlueprint.test.ts b/packages/frontend-plugin-api/src/extensions/ThemeBlueprint.test.ts
new file mode 100644
index 0000000000..d3d05a5e68
--- /dev/null
+++ b/packages/frontend-plugin-api/src/extensions/ThemeBlueprint.test.ts
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2024 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { AppTheme } from '@backstage/core-plugin-api';
+import { ThemeBlueprint } from './ThemeBlueprint';
+import { createExtensionTester } from '@backstage/frontend-test-utils';
+
+describe('ThemeBlueprint', () => {
+  const theme = {
+    id: 'light',
+    colors: { primary: 'blue' },
+    variant: 'dark',
+    title: 'lols',
+    Provider: (_: { children: React.ReactNode }) => null,
+  } as AppTheme;
+
+  it('should create an extension with sensible defaults', () => {
+    expect(
+      // todo(blam): we can't inject theme.id as the name here like the old extension creator.
+      // Wonder if theres a better solution.
+      ThemeBlueprint.make({ name: 'blob', params: { theme } }),
+    ).toMatchInlineSnapshot(`
+      {
+        "$$type": "@backstage/ExtensionDefinition",
+        "attachTo": {
+          "id": "app",
+          "input": "themes",
+        },
+        "configSchema": undefined,
+        "disabled": false,
+        "factory": [Function],
+        "inputs": {},
+        "kind": "theme",
+        "name": "blob",
+        "namespace": "app",
+        "output": [
+          [Function],
+        ],
+        "toString": [Function],
+        "version": "v2",
+      }
+    `);
+  });
+
+  it('should return the theme as an themeDataRef', async () => {
+    const extension = ThemeBlueprint.make({ name: 'blob', params: { theme } });
+
+    expect(
+      createExtensionTester(extension).data(ThemeBlueprint.dataRefs.theme),
+    ).toEqual(theme);
+  });
+});
diff --git a/packages/frontend-plugin-api/src/extensions/ThemeBlueprint.ts b/packages/frontend-plugin-api/src/extensions/ThemeBlueprint.ts
new file mode 100644
index 0000000000..4ddb5a298a
--- /dev/null
+++ b/packages/frontend-plugin-api/src/extensions/ThemeBlueprint.ts
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2024 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { AppTheme } from '@backstage/core-plugin-api';
+import { createExtensionBlueprint } from '../wiring';
+import { createThemeExtension } from './createThemeExtension';
+
+export const ThemeBlueprint = createExtensionBlueprint({
+  kind: 'theme',
+  namespace: 'app',
+  attachTo: { id: 'app', input: 'themes' },
+  output: [createThemeExtension.themeDataRef],
+  dataRefs: {
+    theme: createThemeExtension.themeDataRef,
+  },
+  factory: ({ theme }: { theme: AppTheme }) => [
+    createThemeExtension.themeDataRef(theme),
+  ],
+});