diff --git a/.changeset/remove-createPublicSignInApp.md b/.changeset/remove-createPublicSignInApp.md
new file mode 100644
index 0000000000..2d80d4790b
--- /dev/null
+++ b/.changeset/remove-createPublicSignInApp.md
@@ -0,0 +1,5 @@
+---
+'@backstage/frontend-defaults': minor
+---
+
+**BREAKING**: Removed the deprecated `createPublicSignInApp` function. Use `createApp` from `@backstage/frontend-defaults` with `appModulePublicSignIn` from `@backstage/plugin-app/alpha` instead.
diff --git a/docs/tutorials/enable-public-entry.md b/docs/tutorials/enable-public-entry.md
index e430768785..a1321dca05 100644
--- a/docs/tutorials/enable-public-entry.md
+++ b/docs/tutorials/enable-public-entry.md
@@ -107,10 +107,11 @@ If your app uses the new frontend system, you can still use the public entry poi
 ```tsx title="in packages/app/src/index-public-experimental.tsx"
 import ReactDOM from 'react-dom/client';
 import { signInPageModule } from './overrides/SignInPage';
-import { createPublicSignInApp } from '@backstage/frontend-defaults';
+import { appModulePublicSignIn } from '@backstage/plugin-app/alpha';
+import { createApp } from '@backstage/frontend-defaults';
 
-const app = createPublicSignInApp({
-  features: [signInPageModule],
+const app = createApp({
+  features: [signInPageModule, appModulePublicSignIn],
 });
 
 ReactDOM.createRoot(document.getElementById('root')!).render(app.createRoot());
diff --git a/packages/frontend-defaults/report.api.md b/packages/frontend-defaults/report.api.md
index 75392d2dc1..bc620c95a3 100644
--- a/packages/frontend-defaults/report.api.md
+++ b/packages/frontend-defaults/report.api.md
@@ -37,11 +37,6 @@ export interface CreateAppOptions {
   features?: (FrontendFeature | FrontendFeatureLoader)[];
 }
 
-// @public @deprecated (undocumented)
-export function createPublicSignInApp(options?: CreateAppOptions): {
-  createRoot(): JSX_2;
-};
-
 // @public (undocumented)
 export function discoverAvailableFeatures(config: Config): {
   features: (FrontendFeature | FrontendFeatureLoader)[];
diff --git a/packages/frontend-defaults/src/createPublicSignInApp.test.tsx b/packages/frontend-defaults/src/createPublicSignInApp.test.tsx
deleted file mode 100644
index 398dbcbf4a..0000000000
--- a/packages/frontend-defaults/src/createPublicSignInApp.test.tsx
+++ /dev/null
@@ -1,124 +0,0 @@
-/*
- * 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 { createFrontendModule } from '@backstage/frontend-plugin-api';
-import { SignInPageBlueprint } from '@backstage/plugin-app-react';
-import { render, screen, waitFor } from '@testing-library/react';
-import { useEffect } from 'react';
-import { createPublicSignInApp } from './createPublicSignInApp';
-import { mockApis } from '@backstage/test-utils';
-
-describe('createPublicSignInApp', () => {
-  beforeEach(() => {
-    jest.resetAllMocks();
-  });
-
-  it('should render a sign-in page', async () => {
-    const app = createPublicSignInApp({
-      advanced: {
-        configLoader: async () => ({ config: mockApis.config() }),
-      },
-      features: [
-        createFrontendModule({
-          pluginId: 'app',
-          extensions: [
-            SignInPageBlueprint.make({
-              params: {
-                loader: async () => () => <div>Sign in page</div>,
-              },
-            }),
-          ],
-        }),
-      ],
-    });
-
-    render(app.createRoot());
-
-    await expect(
-      screen.findByText('Sign in page'),
-    ).resolves.toBeInTheDocument();
-  });
-
-  it('should render the form redirect on sign-in', async () => {
-    const submitSpy = jest
-      .spyOn(HTMLFormElement.prototype, 'submit')
-      .mockReturnValue();
-
-    const app = createPublicSignInApp({
-      advanced: {
-        configLoader: async () => ({ config: mockApis.config() }),
-      },
-      features: [
-        createFrontendModule({
-          pluginId: 'app',
-          extensions: [
-            SignInPageBlueprint.make({
-              params: {
-                loader:
-                  async () =>
-                  ({ onSignInSuccess }) => {
-                    useEffect(() => {
-                      onSignInSuccess(
-                        mockApis.identity({ token: 'mock-token' }),
-                      );
-                    }, [onSignInSuccess]);
-                    return <div />;
-                  },
-              },
-            }),
-          ],
-        }),
-      ],
-    });
-
-    const { baseElement } = render(app.createRoot());
-
-    await waitFor(() => {
-      expect(submitSpy).toHaveBeenCalled();
-    });
-
-    expect(baseElement).toMatchInlineSnapshot(`
-      <body
-        data-theme-mode="light"
-        data-theme-name="backstage"
-        data-unified-theme-stack="[{"mode":"light","name":"backstage"}]"
-      >
-        <div>
-          <form
-            action="http://localhost/"
-            method="POST"
-            style="visibility: hidden;"
-          >
-            <input
-              name="type"
-              type="hidden"
-              value="sign-in"
-            />
-            <input
-              name="token"
-              type="hidden"
-              value="mock-token"
-            />
-            <input
-              type="submit"
-              value="Continue"
-            />
-          </form>
-        </div>
-      </body>
-    `);
-  });
-});
diff --git a/packages/frontend-defaults/src/createPublicSignInApp.tsx b/packages/frontend-defaults/src/createPublicSignInApp.tsx
deleted file mode 100644
index 0015d9403f..0000000000
--- a/packages/frontend-defaults/src/createPublicSignInApp.tsx
+++ /dev/null
@@ -1,29 +0,0 @@
-/*
- * Copyright 2025 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 { appModulePublicSignIn } from '@backstage/plugin-app/alpha';
-import { CreateAppOptions, createApp } from './createApp';
-
-/**
- * @public
- * @deprecated Use {@link @backstage/plugin-app/alpha#appModulePublicSignIn} instead.
- */
-export function createPublicSignInApp(options?: CreateAppOptions) {
-  return createApp({
-    ...options,
-    features: [...(options?.features ?? []), appModulePublicSignIn],
-  });
-}
diff --git a/packages/frontend-defaults/src/index.ts b/packages/frontend-defaults/src/index.ts
index 37ec62e794..c7f3e468a2 100644
--- a/packages/frontend-defaults/src/index.ts
+++ b/packages/frontend-defaults/src/index.ts
@@ -21,7 +21,6 @@
  */
 
 export { createApp, type CreateAppOptions } from './createApp';
-export { createPublicSignInApp } from './createPublicSignInApp';
 export { discoverAvailableFeatures } from './discovery';
 export { resolveAsyncFeatures } from './resolution';
 export { maybeCreateErrorPage } from './maybeCreateErrorPage';