diff --git a/lib/core/di/di.dart b/lib/core/di/di.dart
index 67ec86cc..115de91c 100644
--- a/lib/core/di/di.dart
+++ b/lib/core/di/di.dart
@@ -1,9 +1,13 @@
+import 'dart:io';
+
 import 'package:connectivity_plus/connectivity_plus.dart';
+import 'package:cookie_jar/cookie_jar.dart';
 import 'package:dio/dio.dart';
 import 'package:flutter_secure_storage/flutter_secure_storage.dart';
 import 'package:get_it/get_it.dart';
 import 'package:hive_ce_flutter/hive_flutter.dart';
 import 'package:logger/logger.dart';
+import 'package:path_provider/path_provider.dart';
 
 import '../../features/auth/data/remote/auth_api_client.dart';
 import '../../features/auth/data/repositories/auth_repository_impl.dart';
@@ -42,9 +46,12 @@ import '../../features/workouts/execution/data/repositories/workout_execution_re
 import '../../features/workouts/execution/domain/repositories/workout_execution_repository.dart';
 import '../../features/workouts/overview/data/repositories/workouts_overview_repository_impl.dart';
 import '../../features/workouts/overview/domain/repositories/workouts_overview_repository.dart';
+import '../network/api_paths.dart';
 import '../network/dio_setup.dart';
 import '../services/fitness_start_progress_storage/fitness_start_progress_storage.dart';
 import '../services/fitness_start_progress_storage/hive_fitness_start_progress_storage.dart';
+import '../services/guest_session_storage/cookie_jar_guest_session_storage.dart';
+import '../services/guest_session_storage/guest_session_storage.dart';
 import '../services/network/network_service.dart';
 import '../services/network/network_service_impl.dart';
 import '../services/token_storage/secure_token_storage.dart';
@@ -63,6 +70,13 @@ Future<void> setupDI() async {
   final fitnessStartProgressBox = await Hive.openBox<dynamic>(
     HiveFitnessStartProgressStorage.boxName,
   );
+  final supportDirectory = await getApplicationSupportDirectory();
+  final cookiesDirectory = Directory(
+    '${supportDirectory.path}/guest_cookies',
+  );
+  final cookieJar = PersistCookieJar(
+    storage: FileStorage(cookiesDirectory.path),
+  );
 
   // Logger
   di.registerLazySingleton<Logger>(() => createLogger());
@@ -90,12 +104,20 @@ Future<void> setupDI() async {
     () => HiveFitnessStartProgressStorage(fitnessStartProgressBox),
     dispose: (_) => fitnessStartProgressBox.close(),
   );
+  di.registerLazySingleton<CookieJar>(() => cookieJar);
+  di.registerLazySingleton<GuestSessionStorage>(
+    () => CookieJarGuestSessionStorage(
+      di<CookieJar>(),
+      Uri.parse(ApiPaths.baseUrl),
+    ),
+  );
 
   // Authentication
   di.registerLazySingleton<Dio>(
     () => createDioClient(
       logger: di<AppLogger>(),
       tokenStorage: di<TokenStorage>(),
+      cookieJar: di<CookieJar>(),
     ),
   );
   di.registerLazySingleton<AuthApiClient>(() => AuthApiClient(di<Dio>()));
@@ -167,6 +189,7 @@ Future<void> setupDI() async {
       di<AuthRepository>(),
       di<TokenStorage>(),
       di<FitnessStartProgressStorage>(),
+      di<GuestSessionStorage>(),
       di<AppLogger>(),
     ),
     dispose: (cubit) => cubit.close(),
diff --git a/lib/core/network/dio_setup.dart b/lib/core/network/dio_setup.dart
index f7a24dc0..3a4bcf53 100644
--- a/lib/core/network/dio_setup.dart
+++ b/lib/core/network/dio_setup.dart
@@ -1,4 +1,6 @@
+import 'package:cookie_jar/cookie_jar.dart';
 import 'package:dio/dio.dart';
+import 'package:dio_cookie_manager/dio_cookie_manager.dart';
 import 'package:flutter/foundation.dart';
 
 import '../services/token_storage/token_storage.dart';
@@ -11,6 +13,7 @@ import 'interceptors/logging_interceptor.dart';
 Dio createDioClient({
   required AppLogger logger,
   required TokenStorage tokenStorage,
+  required CookieJar cookieJar,
 }) {
   /// Main Dio instance for all API calls.
   final dio = Dio(_createDioBaseOptions());
@@ -18,6 +21,8 @@ Dio createDioClient({
   /// Separate Dio instance for token refresh only to avoid interceptor loops.
   final refreshDio = Dio(_createDioBaseOptions());
 
+  dio.interceptors.add(CookieManager(cookieJar));
+
   dio.interceptors.add(
     AuthInterceptor(
       tokenStorage,
diff --git a/lib/core/services/guest_session_storage/cookie_jar_guest_session_storage.dart b/lib/core/services/guest_session_storage/cookie_jar_guest_session_storage.dart
new file mode 100644
index 00000000..f5ab414b
--- /dev/null
+++ b/lib/core/services/guest_session_storage/cookie_jar_guest_session_storage.dart
@@ -0,0 +1,17 @@
+import 'package:cookie_jar/cookie_jar.dart';
+
+import 'guest_session_storage.dart';
+
+/// CookieJar-backed implementation of [GuestSessionStorage].
+final class CookieJarGuestSessionStorage implements GuestSessionStorage {
+  final CookieJar _cookieJar;
+  final Uri _baseUri;
+
+  /// Creates an instance of [CookieJarGuestSessionStorage].
+  CookieJarGuestSessionStorage(this._cookieJar, this._baseUri);
+
+  @override
+  Future<void> clear() async {
+    await _cookieJar.delete(_baseUri, true);
+  }
+}
diff --git a/lib/core/services/guest_session_storage/guest_session_storage.dart b/lib/core/services/guest_session_storage/guest_session_storage.dart
new file mode 100644
index 00000000..946004f2
--- /dev/null
+++ b/lib/core/services/guest_session_storage/guest_session_storage.dart
@@ -0,0 +1,5 @@
+/// Abstraction for clearing persisted guest backend session data.
+abstract interface class GuestSessionStorage {
+  /// Clears any guest session data persisted locally.
+  Future<void> clear();
+}
diff --git a/lib/features/auth/presentation/cubits/auth_session_cubit.dart b/lib/features/auth/presentation/cubits/auth_session_cubit.dart
index 6abd5230..5998aa71 100644
--- a/lib/features/auth/presentation/cubits/auth_session_cubit.dart
+++ b/lib/features/auth/presentation/cubits/auth_session_cubit.dart
@@ -6,6 +6,7 @@ import 'package:freezed_annotation/freezed_annotation.dart';
 import '../../../../core/failures/feature/auth/auth_failure.dart';
 import '../../../../core/result/result.dart';
 import '../../../../core/services/fitness_start_progress_storage/fitness_start_progress_storage.dart';
+import '../../../../core/services/guest_session_storage/guest_session_storage.dart';
 import '../../../../core/services/token_storage/token_storage.dart';
 import '../../../../core/utils/logger/app_logger.dart';
 import '../../domain/entities/user.dart';
@@ -25,6 +26,9 @@ final class AuthSessionCubit extends Cubit<AuthSessionState> {
   /// Storage for persisted guest Fitness Start progress.
   final FitnessStartProgressStorage _fitnessStartProgressStorage;
 
+  /// Storage for persisted guest backend session cookies.
+  final GuestSessionStorage _guestSessionStorage;
+
   /// Logger for non-fatal session cleanup errors.
   final AppLogger _logger;
 
@@ -33,6 +37,7 @@ final class AuthSessionCubit extends Cubit<AuthSessionState> {
     this._repository,
     this._tokenStorage,
     this._fitnessStartProgressStorage,
+    this._guestSessionStorage,
     this._logger,
   ) : super(const AuthSessionState.initial());
 
@@ -122,8 +127,22 @@ final class AuthSessionCubit extends Cubit<AuthSessionState> {
     }
   }
 
+  Future<bool> _clearGuestSessionSafely() async {
+    try {
+      await _guestSessionStorage.clear();
+      return true;
+    } catch (e, s) {
+      _logger.e('Failed to clear guest session cookies.', e, s);
+      return false;
+    }
+  }
+
   Future<bool> _clearGuestDataSafely() async {
-    return _clearGuestProgressSafely();
+    final results = await Future.wait([
+      _clearGuestProgressSafely(),
+      _clearGuestSessionSafely(),
+    ]);
+    return results.every((isSuccess) => isSuccess);
   }
 
   Future<void> _clearGuestDataAfterAuthSuccess() async {
diff --git a/pubspec.lock b/pubspec.lock
index fc5f1746..a6d26b23 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -225,6 +225,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.1.2"
+  cookie_jar:
+    dependency: "direct main"
+    description:
+      name: cookie_jar
+      sha256: "963da02c1ef64cb5ac20de948c9e5940aa351f1e34a12b1d327c83d85b7e8fff"
+      url: "https://pub.dev"
+    source: hosted
+    version: "4.0.9"
   coverage:
     dependency: transitive
     description:
@@ -281,6 +289,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "5.9.1"
+  dio_cookie_manager:
+    dependency: "direct main"
+    description:
+      name: dio_cookie_manager
+      sha256: "0db1a7b997a0455e488ac35744c68eed3f2a4280d3ab531835a65641b0a08744"
+      url: "https://pub.dev"
+    source: hosted
+    version: "3.4.0"
   dio_web_adapter:
     dependency: transitive
     description:
@@ -1229,6 +1245,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.4.0"
+  universal_io:
+    dependency: transitive
+    description:
+      name: universal_io
+      sha256: f63cbc48103236abf48e345e07a03ce5757ea86285ed313a6a032596ed9301e2
+      url: "https://pub.dev"
+    source: hosted
+    version: "2.3.1"
   uri:
     dependency: transitive
     description:
diff --git a/pubspec.yaml b/pubspec.yaml
index c6f3e28e..06419637 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -10,7 +10,9 @@ dependencies:
   cached_network_image: ^3.4.1
   carousel_slider: ^5.1.1
   connectivity_plus: ^7.0.0
+  cookie_jar: ^4.0.8
   dio: ^5.9.1
+  dio_cookie_manager: ^3.3.0
   envied: ^1.3.3
   equatable: ^2.0.8
   flutter:
diff --git a/test/features/auth/presentation/cubits/auth_session_cubit_test.dart b/test/features/auth/presentation/cubits/auth_session_cubit_test.dart
index 5158908d..41d755c2 100644
--- a/test/features/auth/presentation/cubits/auth_session_cubit_test.dart
+++ b/test/features/auth/presentation/cubits/auth_session_cubit_test.dart
@@ -5,6 +5,7 @@ import 'package:mockito/mockito.dart';
 import 'package:moveup_flutter/core/failures/feature/auth/auth_failure.dart';
 import 'package:moveup_flutter/core/result/result.dart';
 import 'package:moveup_flutter/core/services/fitness_start_progress_storage/fitness_start_progress_storage.dart';
+import 'package:moveup_flutter/core/services/guest_session_storage/guest_session_storage.dart';
 import 'package:moveup_flutter/core/services/token_storage/token_storage.dart';
 import 'package:moveup_flutter/core/utils/logger/app_logger.dart';
 import 'package:moveup_flutter/features/auth/domain/entities/user.dart';
@@ -17,12 +18,14 @@ import 'auth_session_cubit_test.mocks.dart';
   MockSpec<AuthRepository>(),
   MockSpec<TokenStorage>(),
   MockSpec<FitnessStartProgressStorage>(),
+  MockSpec<GuestSessionStorage>(),
   MockSpec<AppLogger>(),
 ])
 void main() {
   late MockAuthRepository repository;
   late MockTokenStorage tokenStorage;
   late MockFitnessStartProgressStorage progressStorage;
+  late MockGuestSessionStorage guestSessionStorage;
   late MockAppLogger logger;
   late AuthSessionCubit authSessionCubit;
 
@@ -36,17 +39,20 @@ void main() {
     repository = MockAuthRepository();
     tokenStorage = MockTokenStorage();
     progressStorage = MockFitnessStartProgressStorage();
+    guestSessionStorage = MockGuestSessionStorage();
     logger = MockAppLogger();
     authSessionCubit = AuthSessionCubit(
       repository,
       tokenStorage,
       progressStorage,
+      guestSessionStorage,
       logger,
     );
     provideDummy<Result<User, AuthFailure>>(const Success(user));
     when(progressStorage.hasCompletedProgress()).thenAnswer((_) async => false);
     when(progressStorage.saveCompleted()).thenAnswer((_) async {});
     when(progressStorage.clear()).thenAnswer((_) async {});
+    when(guestSessionStorage.clear()).thenAnswer((_) async {});
   });
 
   group('AuthSessionCubit', () {
@@ -63,6 +69,7 @@ void main() {
         verify(tokenStorage.getAccessToken()).called(1);
         verify(progressStorage.hasCompletedProgress()).called(1);
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
         verifyNever(repository.getCurrentUser());
       },
     );
@@ -83,6 +90,7 @@ void main() {
         verify(tokenStorage.getAccessToken()).called(1);
         verify(progressStorage.hasCompletedProgress()).called(1);
         verifyNever(progressStorage.clear());
+        verifyNever(guestSessionStorage.clear());
         verifyNever(repository.getCurrentUser());
       },
     );
@@ -104,6 +112,7 @@ void main() {
         verify(progressStorage.hasCompletedProgress()).called(1);
         verify(logger.e(any, any, any)).called(1);
         verifyNever(progressStorage.clear());
+        verifyNever(guestSessionStorage.clear());
         verifyNever(repository.getCurrentUser());
       },
     );
@@ -124,6 +133,7 @@ void main() {
         verify(tokenStorage.getAccessToken()).called(1);
         verify(repository.getCurrentUser()).called(1);
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
         verifyNever(progressStorage.hasCompletedProgress());
         verifyNever(tokenStorage.deleteAccessToken());
       },
@@ -149,6 +159,7 @@ void main() {
         verify(repository.getCurrentUser()).called(1);
         verify(tokenStorage.deleteAccessToken()).called(1);
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
       },
     );
 
@@ -262,6 +273,7 @@ void main() {
       expect: () => const [AuthSessionState.guest()],
       verify: (_) {
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
       },
     );
 
@@ -276,6 +288,7 @@ void main() {
       expect: () => const <AuthSessionState>[],
       verify: (_) {
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
         verify(logger.e(any, any, any)).called(1);
       },
     );
@@ -288,6 +301,7 @@ void main() {
       expect: () => const <AuthSessionState>[],
       verify: (_) {
         verifyNever(progressStorage.clear());
+        verifyNever(guestSessionStorage.clear());
       },
     );
 
@@ -337,13 +351,14 @@ void main() {
       expect: () => const [AuthSessionState.unauthenticated()],
       verify: (_) {
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
       },
     );
 
     blocTest<AuthSessionCubit, AuthSessionState>(
-      'cancelGuestFlow does not emit unauthenticated when guest progress clear fails',
+      'cancelGuestFlow does not emit unauthenticated when guest session clear fails',
       setUp: () {
-        when(progressStorage.clear()).thenThrow(Exception('storage_error'));
+        when(guestSessionStorage.clear()).thenThrow(Exception('storage_error'));
       },
       build: () => authSessionCubit,
       seed: () => const AuthSessionState.guest(),
@@ -351,6 +366,7 @@ void main() {
       expect: () => const <AuthSessionState>[],
       verify: (_) {
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
         verify(logger.e(any, any, any)).called(1);
       },
     );
@@ -365,6 +381,7 @@ void main() {
       expect: () => const [AuthSessionState.authenticated(user)],
       verify: (_) {
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
       },
     );
 
@@ -375,6 +392,7 @@ void main() {
       expect: () => const [AuthSessionState.unauthenticated()],
       verify: (_) {
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
         verifyNever(repository.getCurrentUser());
         verifyNever(tokenStorage.deleteAccessToken());
       },
@@ -390,6 +408,7 @@ void main() {
       expect: () => const [AuthSessionState.unauthenticated()],
       verify: (_) {
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
         verify(logger.e(any, any, any)).called(1);
         verify(logger.w(any, any, any)).called(1);
       },
@@ -406,6 +425,7 @@ void main() {
       verify: (_) {
         verify(tokenStorage.deleteAccessToken()).called(1);
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
       },
     );
 
@@ -420,6 +440,7 @@ void main() {
       verify: (_) {
         verify(tokenStorage.deleteAccessToken()).called(1);
         verify(progressStorage.clear()).called(1);
+        verify(guestSessionStorage.clear()).called(1);
         verify(logger.e(any, any, any)).called(1);
       },
     );