diff --git a/jest.setup.ts b/jest.setup.ts
index 02f79725bf..fb6110baaa 100644
--- a/jest.setup.ts
+++ b/jest.setup.ts
@@ -9,6 +9,10 @@ jest.doMock('react-native', () => {
       },
       NativeModules: {
         ...ReactNative.NativeModules,
+        RNFBAdMobModule: {},
+        RNFBAdMobInterstitialModule: {},
+        RNFBAdMobRewardedModule: {},
+        RNFBAdsConsentModule: {},
         RNFBAppModule: {
           NATIVE_FIREBASE_APPS: [
             {
@@ -25,13 +29,23 @@ jest.doMock('react-native', () => {
               options: {},
             },
           ],
+          addListener: jest.fn(),
+          eventsAddListener: jest.fn(),
+          eventsNotifyReady: jest.fn(),
+        },
+        RNFBAuthModule: {
+          APP_LANGUAGE: {
+            '[DEFAULT]': 'en-US',
+          },
+          APP_USER: {
+            '[DEFAULT]': 'jestUser',
+          },
+          addAuthStateListener: jest.fn(),
+          addIdTokenListener: jest.fn(),
+          useEmulator: jest.fn(),
         },
-        RNFBPerfModule: {},
-        RNFBAdMobModule: {},
-        RNFBAdMobInterstitialModule: {},
-        RNFBAdMobRewardedModule: {},
-        RNFBAdsConsentModule: {},
         RNFBCrashlyticsModule: {},
+        RNFBPerfModule: {},
       },
     },
     ReactNative,
diff --git a/packages/auth/__tests__/auth.test.ts b/packages/auth/__tests__/auth.test.ts
new file mode 100644
index 0000000000..458a029619
--- /dev/null
+++ b/packages/auth/__tests__/auth.test.ts
@@ -0,0 +1,46 @@
+import auth, { firebase } from '../lib';
+
+describe('Auth', () => {
+  describe('namespace', () => {
+    it('accessible from firebase.app()', () => {
+      const app = firebase.app();
+      expect(app.auth).toBeDefined();
+      expect(app.auth().useEmulator).toBeDefined();
+    });
+  });
+
+  describe('useEmulator()', () => {
+    it('useEmulator requires a string url', () => {
+      // @ts-ignore because we pass an invalid argument...
+      expect(() => auth().useEmulator()).toThrow(
+        'firebase.auth().useEmulator() takes a non-empty string',
+      );
+      expect(() => auth().useEmulator('')).toThrow(
+        'firebase.auth().useEmulator() takes a non-empty string',
+      );
+      // @ts-ignore because we pass an invalid argument...
+      expect(() => auth().useEmulator(123)).toThrow(
+        'firebase.auth().useEmulator() takes a non-empty string',
+      );
+    });
+
+    it('useEmulator requires a well-formed url', () => {
+      // No http://
+      expect(() => auth().useEmulator('localhost:9099')).toThrow(
+        'firebase.auth().useEmulator() unable to parse host and port from url',
+      );
+      // No port
+      expect(() => auth().useEmulator('http://localhost')).toThrow(
+        'firebase.auth().useEmulator() unable to parse host and port from url',
+      );
+    });
+
+    it('useEmulator -> remaps Android loopback to host', () => {
+      const foo = auth().useEmulator('http://localhost:9099');
+      expect(foo).toEqual(['10.0.2.2', 9099]);
+
+      const bar = auth().useEmulator('http://127.0.0.1:9099');
+      expect(bar).toEqual(['10.0.2.2', 9099]);
+    });
+  });
+});
diff --git a/packages/auth/lib/index.d.ts b/packages/auth/lib/index.d.ts
index 8c317ed0d5..ecae068cb5 100644
--- a/packages/auth/lib/index.d.ts
+++ b/packages/auth/lib/index.d.ts
@@ -1640,6 +1640,14 @@ export namespace FirebaseAuthTypes {
      * @param userAccessGroup A string of the keychain id i.e. "TEAMID.com.example.group1"
      */
     useUserAccessGroup(userAccessGroup: string): Promise<null>;
+    /**
+     * Modify this Auth instance to communicate with the Firebase Auth emulator.
+     * This must be called synchronously immediately following the first call to firebase.auth().
+     * Do not use with production credentials as emulator traffic is not encrypted.
+     *
+     * @param url: emulator URL, must have host and port (eg, 'http://localhost:9099')
+     */
+    useEmulator(url: string): void;
   }
 }
 
diff --git a/packages/auth/lib/index.js b/packages/auth/lib/index.js
index da7a2cc59f..367a98b220 100644
--- a/packages/auth/lib/index.js
+++ b/packages/auth/lib/index.js
@@ -334,6 +334,33 @@ class FirebaseAuthModule extends FirebaseModule {
       'firebase.auth().useDeviceLanguage() is unsupported by the native Firebase SDKs.',
     );
   }
+
+  useEmulator(url) {
+    if (!url || !isString(url) || url === '') {
+      throw new Error('firebase.auth().useEmulator() takes a non-empty string');
+    }
+
+    let _url = url;
+    if (isAndroid && _url) {
+      if (_url.startsWith('http://localhost')) {
+        _url = _url.replace('http://localhost', 'http://10.0.2.2');
+      }
+      if (_url.startsWith('http://127.0.0.1')) {
+        _url = _url.replace('http://127.0.0.1', 'http://10.0.2.2');
+      }
+    }
+
+    // Native calls take the host and port split out
+    const hostPortRegex = /^http:\/\/([\w\d.]+):(\d+)$/;
+    const urlMatches = _url.match(hostPortRegex);
+    if (!urlMatches) {
+      throw new Error('firebase.auth().useEmulator() unable to parse host and port from url');
+    }
+    const host = urlMatches[1];
+    const port = parseInt(urlMatches[2], 10);
+    this.native.useEmulator(host, port);
+    return [host, port]; // undocumented return, useful for unit testing
+  }
 }
 
 // import { SDK_VERSION } from '@react-native-firebase/auth';