diff --git a/packages/core-app-api/src/app/App.test.tsx b/packages/core-app-api/src/app/App.test.tsx
index 6ed5d45b86..198048f8cf 100644
--- a/packages/core-app-api/src/app/App.test.tsx
+++ b/packages/core-app-api/src/app/App.test.tsx
@@ -38,7 +38,7 @@ import {
   analyticsApiRef,
 } from '@backstage/core-plugin-api';
 import { generateBoundRoutes, PrivateAppImpl } from './App';
-import { AppThemeProvider } from './AppThemeProvider';
+import { AppComponents } from './types';
 
 describe('generateBoundRoutes', () => {
   it('runs happy path', () => {
@@ -178,13 +178,13 @@ describe('Integration Test', () => {
     }),
   );
 
-  const components = {
+  const components: AppComponents = {
     NotFoundErrorPage: () => null,
     BootErrorPage: () => null,
     Progress: () => null,
     Router: BrowserRouter,
     ErrorBoundaryFallback: () => null,
-    ThemeProvider: AppThemeProvider,
+    ThemeProvider: ({ children }) => <>{children}</>,
   };
 
   it('runs happy paths', async () => {
diff --git a/packages/core-app-api/src/app/AppThemeProvider.tsx b/packages/core-app-api/src/app/AppThemeProvider.tsx
deleted file mode 100644
index aa48a2187d..0000000000
--- a/packages/core-app-api/src/app/AppThemeProvider.tsx
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * Copyright 2020 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 React, { useMemo, useEffect, useState, PropsWithChildren } from 'react';
-import { ThemeProvider } from '@material-ui/core/styles';
-import CssBaseline from '@material-ui/core/CssBaseline';
-import { useApi, appThemeApiRef, AppTheme } from '@backstage/core-plugin-api';
-import { useObservable } from 'react-use';
-
-// This tries to find the most accurate match, but also falls back to less
-// accurate results in order to avoid errors.
-function resolveTheme(
-  themeId: string | undefined,
-  shouldPreferDark: boolean,
-  themes: AppTheme[],
-) {
-  if (themeId !== undefined) {
-    const selectedTheme = themes.find(theme => theme.id === themeId);
-    if (selectedTheme) {
-      return selectedTheme;
-    }
-  }
-
-  if (shouldPreferDark) {
-    const darkTheme = themes.find(theme => theme.variant === 'dark');
-    if (darkTheme) {
-      return darkTheme;
-    }
-  }
-
-  const lightTheme = themes.find(theme => theme.variant === 'light');
-  if (lightTheme) {
-    return lightTheme;
-  }
-
-  return themes[0];
-}
-
-const useShouldPreferDarkTheme = () => {
-  const mediaQuery = useMemo(
-    () => window.matchMedia('(prefers-color-scheme: dark)'),
-    [],
-  );
-  const [shouldPreferDark, setPrefersDark] = useState(mediaQuery.matches);
-
-  useEffect(() => {
-    const listener = (event: MediaQueryListEvent) => {
-      setPrefersDark(event.matches);
-    };
-    mediaQuery.addListener(listener);
-    return () => {
-      mediaQuery.removeListener(listener);
-    };
-  }, [mediaQuery]);
-
-  return shouldPreferDark;
-};
-
-export function AppThemeProvider({ children }: PropsWithChildren<{}>) {
-  const appThemeApi = useApi(appThemeApiRef);
-  const themeId = useObservable(
-    appThemeApi.activeThemeId$(),
-    appThemeApi.getActiveThemeId(),
-  );
-
-  // Browser feature detection won't change over time, so ignore lint rule
-  const shouldPreferDark = Boolean(window.matchMedia)
-    ? useShouldPreferDarkTheme() // eslint-disable-line react-hooks/rules-of-hooks
-    : false;
-
-  const appTheme = resolveTheme(
-    themeId,
-    shouldPreferDark,
-    appThemeApi.getInstalledThemes(),
-  );
-  if (!appTheme) {
-    throw new Error('App has no themes');
-  }
-
-  if (appTheme.Provider) {
-    return <appTheme.Provider children={children} />;
-  }
-
-  // eslint-disable-next-line no-console
-  console.warn(
-    "DEPRECATION WARNING: A provided app theme is using the deprecated 'theme' property " +
-      'and should be migrated to use a Provider instead. ' +
-      'See https://backstage.io/docs/deprecations/TODO for more info.',
-  );
-
-  return (
-    <ThemeProvider theme={appTheme.theme}>
-      <CssBaseline>{children}</CssBaseline>
-    </ThemeProvider>
-  );
-}