diff --git a/packages/react-native/Libraries/AppDelegate/RCTAppDelegate.h b/packages/react-native/Libraries/AppDelegate/RCTAppDelegate.h
index b36e62f230731c..0c84edf4b93487 100644
--- a/packages/react-native/Libraries/AppDelegate/RCTAppDelegate.h
+++ b/packages/react-native/Libraries/AppDelegate/RCTAppDelegate.h
@@ -132,6 +132,14 @@
 /// @return: `true` if the Fabric Renderer is enabled. Otherwise, it returns `false`.
 - (BOOL)fabricEnabled;
 
+/// This method controls whether React Native's new initialization layer is enabled.
+///
+/// @return: `true` if the new initialization layer is enabled. Otherwise returns `false`.
+- (BOOL)bridgelessEnabled;
+
+/// Return the bundle URL for the main bundle.
+- (NSURL *)getBundleURL;
+
 #endif
 
 @end
diff --git a/packages/react-native/Libraries/AppDelegate/RCTAppDelegate.mm b/packages/react-native/Libraries/AppDelegate/RCTAppDelegate.mm
index ecc438ca4a4f7a..b299ac72b15738 100644
--- a/packages/react-native/Libraries/AppDelegate/RCTAppDelegate.mm
+++ b/packages/react-native/Libraries/AppDelegate/RCTAppDelegate.mm
@@ -8,28 +8,41 @@
 #import "RCTAppDelegate.h"
 #import <React/RCTRootView.h>
 #import "RCTAppSetupUtils.h"
+#import "RCTLegacyInteropComponents.h"
 
 #if RCT_NEW_ARCH_ENABLED
 #import <React/CoreModulesPlugins.h>
+#import <React/RCTBundleURLProvider.h>
 #import <React/RCTComponentViewFactory.h>
 #import <React/RCTComponentViewProtocol.h>
 #import <React/RCTCxxBridgeDelegate.h>
+#import <React/RCTFabricSurface.h>
 #import <React/RCTFabricSurfaceHostingProxyRootView.h>
 #import <React/RCTLegacyViewManagerInteropComponentView.h>
+#import <React/RCTSurfaceHostingProxyRootView.h>
 #import <React/RCTSurfacePresenter.h>
 #import <React/RCTSurfacePresenterBridgeAdapter.h>
+#import <ReactCommon/RCTContextContainerHandling.h>
+#if USE_HERMES
+#import <ReactCommon/RCTHermesInstance.h>
+#else
+#import <ReactCommon/RCTJscInstance.h>
+#endif
+#import <ReactCommon/RCTHost+Internal.h>
+#import <ReactCommon/RCTHost.h>
 #import <ReactCommon/RCTTurboModuleManager.h>
+#import <react/bridgeless/JSEngineInstance.h>
 #import <react/config/ReactNativeConfig.h>
 #import <react/renderer/runtimescheduler/RuntimeScheduler.h>
 #import <react/renderer/runtimescheduler/RuntimeSchedulerCallInvoker.h>
-#import "RCTLegacyInteropComponents.h"
 
 static NSString *const kRNConcurrentRoot = @"concurrentRoot";
 
 @interface RCTAppDelegate () <
     RCTTurboModuleManagerDelegate,
     RCTCxxBridgeDelegate,
-    RCTComponentViewFactoryComponentProvider> {
+    RCTComponentViewFactoryComponentProvider,
+    RCTContextContainerHandling> {
   std::shared_ptr<const facebook::react::ReactNativeConfig> _reactNativeConfig;
   facebook::react::ContextContainer::Shared _contextContainer;
   std::shared_ptr<facebook::react::RuntimeScheduler> _runtimeScheduler;
@@ -38,7 +51,11 @@ @interface RCTAppDelegate () <
 
 #endif
 
-@implementation RCTAppDelegate
+@implementation RCTAppDelegate {
+#if RCT_NEW_ARCH_ENABLED
+  RCTHost *_reactHost;
+#endif
+}
 
 #if RCT_NEW_ARCH_ENABLED
 - (instancetype)init
@@ -55,26 +72,44 @@ - (instancetype)init
 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
 {
   BOOL enableTM = NO;
+  BOOL enableBridgeless = NO;
 #if RCT_NEW_ARCH_ENABLED
   enableTM = self.turboModuleEnabled;
+  enableBridgeless = self.bridgelessEnabled;
 #endif
+
   RCTAppSetupPrepareApp(application, enableTM);
 
-  if (!self.bridge) {
-    self.bridge = [self createBridgeWithDelegate:self launchOptions:launchOptions];
-  }
+  UIView *rootView;
+
+  if (enableBridgeless) {
 #if RCT_NEW_ARCH_ENABLED
-  self.bridgeAdapter = [[RCTSurfacePresenterBridgeAdapter alloc] initWithBridge:self.bridge
-                                                               contextContainer:_contextContainer];
-  self.bridge.surfacePresenter = self.bridgeAdapter.surfacePresenter;
+    [self createReactHost];
+    RCTFabricSurface *surface = [_reactHost createSurfaceWithModuleName:self.moduleName
+                                                      initialProperties:launchOptions];
 
-  [self unstable_registerLegacyComponents];
-  [RCTComponentViewFactory currentComponentViewFactory].thirdPartyFabricComponentsProvider = self;
-#endif
+    RCTSurfaceHostingProxyRootView *surfaceHostingProxyRootView = [[RCTSurfaceHostingProxyRootView alloc]
+        initWithSurface:surface
+        sizeMeasureMode:RCTSurfaceSizeMeasureModeWidthExact | RCTSurfaceSizeMeasureModeHeightExact
+         moduleRegistry:[_reactHost getModuleRegistry]];
 
-  NSDictionary *initProps = [self prepareInitialProps];
-  UIView *rootView = [self createRootViewWithBridge:self.bridge moduleName:self.moduleName initProps:initProps];
+    rootView = (RCTRootView *)surfaceHostingProxyRootView;
+#endif
+  } else {
+    if (!self.bridge) {
+      self.bridge = [self createBridgeWithDelegate:self launchOptions:launchOptions];
+    }
+#if RCT_NEW_ARCH_ENABLED
+    self.bridgeAdapter = [[RCTSurfacePresenterBridgeAdapter alloc] initWithBridge:self.bridge
+                                                                 contextContainer:_contextContainer];
+    self.bridge.surfacePresenter = self.bridgeAdapter.surfacePresenter;
 
+    [self unstable_registerLegacyComponents];
+    [RCTComponentViewFactory currentComponentViewFactory].thirdPartyFabricComponentsProvider = self;
+#endif
+    NSDictionary *initProps = [self prepareInitialProps];
+    rootView = [self createRootViewWithBridge:self.bridge moduleName:self.moduleName initProps:initProps];
+  }
   self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
   UIViewController *rootViewController = [self createRootViewController];
   [self setRootView:rootView toRootViewController:rootViewController];
@@ -198,6 +233,11 @@ - (BOOL)fabricEnabled
   return YES;
 }
 
+- (BOOL)bridgelessEnabled
+{
+  return YES;
+}
+
 #pragma mark - New Arch Utilities
 
 - (void)unstable_registerLegacyComponents
@@ -207,6 +247,43 @@ - (void)unstable_registerLegacyComponents
   }
 }
 
+- (void)createReactHost
+{
+  __weak __typeof(self) weakSelf = self;
+  _reactHost = [[RCTHost alloc] initWithBundleURL:[self getBundleURL]
+                                     hostDelegate:nil
+                       turboModuleManagerDelegate:self
+                                 jsEngineProvider:^std::shared_ptr<facebook::react::JSEngineInstance>() {
+                                   return [weakSelf createJSEngineInstance];
+                                 }];
+  [_reactHost setBundleURLProvider:^NSURL *() {
+    return [weakSelf getBundleURL];
+  }];
+  [_reactHost setContextContainerHandler:self];
+  [_reactHost start];
+}
+
+- (std::shared_ptr<facebook::react::JSEngineInstance>)createJSEngineInstance
+{
+#if USE_HERMES
+  return std::make_shared<facebook::react::RCTHermesInstance>(_reactNativeConfig, nullptr);
+#else
+  return std::make_shared<facebook::react::RCTJscInstance>();
+#endif
+}
+
+- (void)didCreateContextContainer:(std::shared_ptr<facebook::react::ContextContainer>)contextContainer
+{
+  contextContainer->insert("ReactNativeConfig", _reactNativeConfig);
+}
+
+- (NSURL *)getBundleURL
+{
+  [NSException raise:@"RCTAppDelegate::getBundleURL not implemented"
+              format:@"Subclasses must implement a valid getBundleURL method"];
+  return nullptr;
+}
+
 #endif
 
 @end
diff --git a/packages/react-native/Libraries/AppDelegate/React-RCTAppDelegate.podspec b/packages/react-native/Libraries/AppDelegate/React-RCTAppDelegate.podspec
index 8df2d6a7288e46..56b015046553db 100644
--- a/packages/react-native/Libraries/AppDelegate/React-RCTAppDelegate.podspec
+++ b/packages/react-native/Libraries/AppDelegate/React-RCTAppDelegate.podspec
@@ -20,13 +20,14 @@ folly_flags = ' -DFOLLY_NO_CONFIG -DFOLLY_MOBILE=1 -DFOLLY_USE_LIBCPP=1'
 folly_compiler_flags = folly_flags + ' ' + '-Wno-comma -Wno-shorten-64-to-32'
 
 is_new_arch_enabled = ENV["RCT_NEW_ARCH_ENABLED"] == "1"
+use_hermes =  ENV['USE_HERMES'] == nil || ENV['USE_HERMES'] == '1'
+use_frameworks = ENV['USE_FRAMEWORKS'] != nil
+
 new_arch_enabled_flag = (is_new_arch_enabled ? " -DRCT_NEW_ARCH_ENABLED" : "")
 is_fabric_enabled = is_new_arch_enabled || ENV["RCT_FABRIC_ENABLED"]
 fabric_flag = (is_fabric_enabled ? " -DRN_FABRIC_ENABLED" : "")
-other_cflags = "$(inherited)" + folly_flags + new_arch_enabled_flag + fabric_flag
-
-use_hermes = ENV['USE_HERMES'] == '1'
-use_frameworks = ENV['USE_FRAMEWORKS'] != nil
+hermes_flag = (use_hermes ? " -DUSE_HERMES" : "")
+other_cflags = "$(inherited)" + folly_flags + new_arch_enabled_flag + fabric_flag + hermes_flag
 
 header_search_paths = [
   "$(PODS_TARGET_SRCROOT)/../../ReactCommon",
diff --git a/packages/rn-tester/RNTester/AppDelegate.mm b/packages/rn-tester/RNTester/AppDelegate.mm
index 1e8616f9ad0881..35274d73bc24ad 100644
--- a/packages/rn-tester/RNTester/AppDelegate.mm
+++ b/packages/rn-tester/RNTester/AppDelegate.mm
@@ -123,6 +123,11 @@ - (void)application:(__unused UIApplication *)application
 {
   return @{@"RNTMyNativeView" : RNTMyNativeViewComponentView.class};
 }
+
+- (NSURL *)getBundleURL
+{
+  return [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"js/RNTesterApp.ios"];
+}
 #endif
 
 @end