diff --git a/.github/workflows/microsoft-build-rntester-prebuilt.yml b/.github/workflows/microsoft-build-rntester-prebuilt.yml
new file mode 100644
index 000000000000..cde84544f1de
--- /dev/null
+++ b/.github/workflows/microsoft-build-rntester-prebuilt.yml
@@ -0,0 +1,71 @@
+name: Build RNTester (Prebuilt)
+
+on:
+  workflow_call:
+
+jobs:
+  build-rntester-prebuilt:
+    name: "Prebuilt ${{ matrix.platform }}, ${{ matrix.arch }}"
+    runs-on: macos-26
+    timeout-minutes: 60
+    strategy:
+      fail-fast: false
+      matrix:
+        platform: [macos, ios, visionos]
+        arch: [newarch]
+        include:
+          # Platform-specific properties
+          - platform: macos
+            sdk: macosx
+            scheme: RNTester-macOS
+            packager_platform: macos
+          - platform: ios
+            sdk: iphonesimulator
+            scheme: RNTester
+            packager_platform: ios
+          - platform: visionos
+            sdk: xrsimulator
+            scheme: RNTester-visionOS
+            packager_platform: ios
+          # Architecture-specific properties
+          - arch: newarch
+            new_arch_enabled: '1'
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          filter: blob:none
+          fetch-depth: 0
+
+      - name: Setup toolchain
+        uses: ./.github/actions/microsoft-setup-toolchain
+        with:
+          node-version: '22'
+          platform: ${{ matrix.platform }}
+          project-root: 'packages/rn-tester'
+
+      - name: Install npm dependencies
+        run: yarn install
+
+      - name: Download prebuilt xcframework
+        uses: actions/download-artifact@v4
+        with:
+          name: ReactCoreDebug.xcframework.tar.gz
+          path: /tmp/prebuilt
+
+      - name: Install Pods (with prebuilt)
+        working-directory: packages/rn-tester
+        env:
+          RCT_NEW_ARCH_ENABLED: ${{ matrix.new_arch_enabled }}
+          RCT_TESTONLY_RNCORE_TARBALL_PATH: /tmp/prebuilt/ReactCoreDebug.xcframework.tar.gz
+        run: |
+          set -eox pipefail
+          bundle install
+          bundle exec pod install --verbose
+
+      - name: Build ${{ matrix.scheme }}
+        env:
+          USE_CCACHE: 0
+        run: |
+          set -eox pipefail
+          .ado/scripts/xcodebuild.sh packages/rn-tester/RNTesterPods.xcworkspace ${{ matrix.sdk }} Debug ${{ matrix.scheme }} build
diff --git a/.github/workflows/microsoft-build-rntester.yml b/.github/workflows/microsoft-build-rntester.yml
index 20797e8f8d07..10ef532cc315 100644
--- a/.github/workflows/microsoft-build-rntester.yml
+++ b/.github/workflows/microsoft-build-rntester.yml
@@ -5,9 +5,11 @@ on:
 
 jobs:
   build-rntester:
-    name: "${{ matrix.platform }}, ${{ matrix.arch }}"
+    name: "${{ matrix.platform }}, ${{ matrix.arch }}${{ matrix.use_frameworks && ', DynamicFrameworks' || '' }}"
     runs-on: macos-26
     timeout-minutes: 90
+    # DynamicFrameworks is experimental; don't block PRs on it (matches upstream)
+    continue-on-error: ${{ matrix.use_frameworks == 'dynamic' }}
     strategy:
       fail-fast: false
       matrix:
@@ -32,6 +34,14 @@ jobs:
             new_arch_enabled: '0'
           - arch: newarch
             new_arch_enabled: '1'
+          # DynamicFrameworks variant (matches upstream test_ios_rntester_dynamic_frameworks)
+          - platform: ios
+            arch: newarch
+            sdk: iphonesimulator
+            scheme: RNTester
+            packager_platform: ios
+            new_arch_enabled: '1'
+            use_frameworks: dynamic
 
     steps:
       - uses: actions/checkout@v4
@@ -55,6 +65,9 @@ jobs:
           RCT_NEW_ARCH_ENABLED: ${{ matrix.new_arch_enabled }}
         run: |
           set -eox pipefail
+          if [[ -n "${{ matrix.use_frameworks }}" ]]; then
+            export USE_FRAMEWORKS="${{ matrix.use_frameworks }}"
+          fi
           bundle install
           bundle exec pod install --verbose
 
diff --git a/.github/workflows/microsoft-pr.yml b/.github/workflows/microsoft-pr.yml
index ee3a01e5dd01..94345c5ae6e6 100644
--- a/.github/workflows/microsoft-pr.yml
+++ b/.github/workflows/microsoft-pr.yml
@@ -112,24 +112,24 @@ jobs:
         with:
           filter: blob:none
           fetch-depth: 0
-      
+
       - name: Setup toolchain
         uses: ./.github/actions/microsoft-setup-toolchain
         with:
           node-version: '22'
-      
+
       - name: Install npm dependencies
         run: yarn install
-      
+
       - name: Run Jest tests
         run: yarn test-ci
-      
+
       - name: Run Flow type checker
         run: yarn flow-check
-      
+
       - name: Run ESLint
         run: yarn lint
-      
+
       - name: Run Prettier format check
         run: yarn format-check
 
@@ -143,6 +143,12 @@ jobs:
     permissions: {}
     uses: ./.github/workflows/microsoft-prebuild-macos-core.yml
 
+  build-rntester-prebuilt:
+    name: "Build RNTester (Prebuilt)"
+    permissions: {}
+    needs: [prebuild-macos-core]
+    uses: ./.github/workflows/microsoft-build-rntester-prebuilt.yml
+
   test-react-native-macos-init:
     name: "Test react-native-macos init"
     permissions: {}
@@ -170,6 +176,7 @@ jobs:
       - javascript-tests
       - build-rntester
       - prebuild-macos-core
+      - build-rntester-prebuilt
       - test-react-native-macos-init
       # - react-native-test-app-integration
     steps:
diff --git a/packages/react-native/scripts/ios-prebuild/React-umbrella.h b/packages/react-native/scripts/ios-prebuild/React-umbrella.h
index 45b365b92b9a..7567e809d9ee 100644
--- a/packages/react-native/scripts/ios-prebuild/React-umbrella.h
+++ b/packages/react-native/scripts/ios-prebuild/React-umbrella.h
@@ -6,7 +6,11 @@
  */
 
 #ifdef __OBJC__
+#if !TARGET_OS_OSX // [macOS]
 #import <UIKit/UIKit.h>
+#else // [macOS
+#import <AppKit/AppKit.h>
+#endif // macOS]
 #else
 #ifndef FOUNDATION_EXPORT
 #if defined(__cplusplus)