diff --git a/.gitignore b/.gitignore
index ec29f307843..95af0ee314e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -44,6 +44,9 @@ package-lock.json
 *BundleArtifacts*
 *ReactAssets*
 
+# RN Tester sync cache (created by scripts/sync-rn-tester.ps1)
+.rn-cache/
+
 #OS junk files
 [Tt]humbs.db
 *.DS_Store
diff --git a/scripts/README.md b/scripts/README.md
new file mode 100644
index 00000000000..a9d3f3891c3
--- /dev/null
+++ b/scripts/README.md
@@ -0,0 +1,103 @@
+# RNTester Sync Script
+
+A PowerShell script that syncs React Native Windows files with upstream React Native commits. Fixes `yarn validate-overrides` errors and keeps IntegrationTests up to date.
+
+## 🎯 What It Does
+
+**Syncs TWO things from upstream React Native:**
+1. **RNTester files** → `packages/@react-native/tester/js/` (fixes yarn validate-overrides)
+2. **IntegrationTests** → `vnext/ReactCopies/IntegrationTests/` (keeps tests current)
+
+**Uses the commit hash YOU provide** - so you control exactly which React Native version to sync from.
+
+## 🚀 Quick Start
+
+```powershell
+# Preview what will change (recommended first)
+.\scripts\sync-rn-tester.ps1 -CommitHash '1a6d466f1' -DryRun
+
+# Apply the changes
+.\scripts\sync-rn-tester.ps1 -CommitHash '1a6d466f1'
+
+# Verify it worked
+yarn validate-overrides
+```
+
+## 📖 Usage
+
+### Basic Command
+```powershell
+.\sync-rn-tester.ps1 -CommitHash <your-commit-hash>
+```
+
+### Options
+- `-CommitHash` (required) - React Native commit to sync from
+- `-DryRun` - Preview changes without modifying files
+- `-ForceClone` - Force fresh download (if cache issues)
+
+## 🔍 Finding the Right Commit Hash
+
+### From GitHub Compare URL
+```
+https://github.com/facebook/react-native/compare/old...NEW
+Use the NEW commit hash (after the ...)
+Example: 1a6d466f1
+```
+
+### From Command Line
+```bash
+git ls-remote https://github.com/facebook/react-native.git main
+```
+
+### From GitHub Web
+Visit: https://github.com/facebook/react-native/commits/main
+
+## ⚡ Performance
+
+- **First run**: Downloads React Native (~30-60 seconds)
+- **Later runs**: Uses cache (~5-10 seconds)
+- **Cache location**: `[YourRepoParent]/.rn-cache/`
+
+## 🛡️ Safety
+
+- **Preview mode**: Use `-DryRun` to see changes first
+- **Git tracked**: All changes show up in `git diff`
+- **Limited scope**: Only touches RNTester and IntegrationTests
+- **Auto-detection**: Finds your repo automatically
+
+## 💡 Common Workflow
+
+```powershell
+# 1. Save your work
+git add . && git commit -m "checkpoint before sync"
+
+# 2. Preview the sync
+.\scripts\sync-rn-tester.ps1 -CommitHash 'TARGET_COMMIT' -DryRun
+
+# 3. Apply the sync  
+.\scripts\sync-rn-tester.ps1 -CommitHash 'TARGET_COMMIT'
+
+# 4. Verify and commit
+yarn validate-overrides
+git add . && git commit -m "sync: RNTester with TARGET_COMMIT"
+```
+
+## 🔧 Troubleshooting
+
+**"Could not auto-detect repository root"**
+→ Run from inside react-native-windows directory
+
+**"Failed to checkout commit"**  
+→ Try: `.\sync-rn-tester.ps1 -CommitHash 'abc123' -ForceClone`
+
+**yarn validate-overrides still fails**
+→ Double-check the commit hash is correct
+
+## 📁 What Gets Modified
+
+✅ **Modified**: RNTester examples and IntegrationTests only  
+❌ **Never touched**: Your app code, Windows native code, build files
+
+---
+
+**That's it!** Simple script, one mode, syncs both areas you need for React Native Windows integration work.
\ No newline at end of file
diff --git a/scripts/sync-rn-tester.ps1 b/scripts/sync-rn-tester.ps1
new file mode 100644
index 00000000000..d6b0ad0d1b9
--- /dev/null
+++ b/scripts/sync-rn-tester.ps1
@@ -0,0 +1,418 @@
+param(
+    [Parameter(Mandatory=$true)]
+    [string]$CommitHash,
+    [string]$ReactNativeRepo = "https://github.com/facebook/react-native.git",
+    [string]$WindowsRepoRoot = $null,     # Auto-detect current repo root
+    [string]$TesterPath = $null,          # Auto-detect tester path  
+    [string]$IntegrationTestsPath = $null, # Auto-detect vnext\ReactCopies\IntegrationTests path
+    [string]$CacheDir = $null,            # Auto-detect cache location
+    [switch]$DryRun = $false,
+    [switch]$ForceClone = $false
+)
+
+# Colors for output
+function Write-Success { param($Message) Write-Host $Message -ForegroundColor Green }
+function Write-Warning { param($Message) Write-Host $Message -ForegroundColor Yellow }
+function Write-Error { param($Message) Write-Host $Message -ForegroundColor Red }
+function Write-Info { param($Message) Write-Host $Message -ForegroundColor Cyan }
+
+# Help function
+function Show-Help {
+    Write-Host @"
+RNTester Sync Script - Sync React Native Tester files with upstream commits
+
+USAGE:
+    .\sync-rn-tester.ps1 -CommitHash <hash> [options]
+
+REQUIRED:
+    -CommitHash <string>    The React Native commit hash to sync from
+
+OPTIONS:
+    -DryRun                Preview changes without actually modifying files
+    -ForceClone            Force fresh clone (ignore cache)
+
+EXAMPLES:
+    # Sync RNTester + IntegrationTests (main use case)
+    .\sync-rn-tester.ps1 -CommitHash "1a6d466f1"
+
+    # Preview changes first (recommended)
+    .\sync-rn-tester.ps1 -CommitHash "1a6d466f1" -DryRun
+
+    # Force fresh clone and sync
+    .\sync-rn-tester.ps1 -CommitHash "1a6d466f1" -ForceClone
+
+    # Force fresh clone and sync
+    .\sync-rn-tester.ps1 -CommitHash "1a6d466f1" -ForceClone
+
+CACHE:
+    Repository is automatically cached in parent directory of your repo:
+    [YourRepoParent]\.rn-cache\react-native
+    
+    You can override with: -CacheDir "C:\your\custom\path"
+    Use -ForceClone to refresh cache if needed
+
+AUTO-DETECTION:
+    Script auto-detects your repository root and paths
+    Override with: -WindowsRepoRoot "C:\path\to\react-native-windows"
+"@ -ForegroundColor White
+}
+
+# Auto-detect paths if not provided
+if (-not $WindowsRepoRoot) {
+    # Find the react-native-windows root by looking for package.json with "react-native-windows" in name
+    $CurrentDir = Get-Location
+    $SearchDir = $CurrentDir
+    
+    while ($SearchDir) {
+        $PackageJson = Join-Path $SearchDir "package.json"
+        if (Test-Path $PackageJson) {
+            try {
+                $PackageContent = Get-Content $PackageJson -Raw | ConvertFrom-Json
+                if ($PackageContent.name -eq "react-native-windows" -or 
+                    $PackageContent.name -eq "react-native-windows-repo" -or 
+                    $SearchDir.Name -eq "react-native-windows") {
+                    $WindowsRepoRoot = $SearchDir.Path
+                    break
+                }
+            } catch {
+                # Ignore JSON parsing errors and continue searching
+            }
+        }
+        $SearchDir = $SearchDir.Parent
+    }
+    
+    if (-not $WindowsRepoRoot) {
+        Write-Error "Could not auto-detect react-native-windows repository root. Please run from within the repo or specify -WindowsRepoRoot"
+        exit 1
+    }
+}
+
+if (-not $TesterPath) {
+    $TesterPath = Join-Path $WindowsRepoRoot "packages\@react-native\tester"
+}
+
+if (-not $IntegrationTestsPath) {
+    $IntegrationTestsPath = Join-Path $WindowsRepoRoot "vnext\ReactCopies\IntegrationTests"
+}
+
+if (-not $CacheDir) {
+    # Use parent directory of WindowsRepoRoot for cache
+    $ParentDir = Split-Path $WindowsRepoRoot -Parent
+    $CacheDir = Join-Path $ParentDir ".rn-cache"
+}
+
+# List of directories that should be exact copies (from yarn validate-overrides)
+$OverrideDirectories = @(
+    "js\components",
+    "js\examples\Accessibility",
+    "js\examples\ActionSheetIOS",
+    "js\examples\ActivityIndicator",
+    "js\examples\Alert",
+    "js\examples\Animated",
+    "js\examples\AnimatedGratuitousApp",
+    "js\examples\Appearance",
+    "js\examples\AppState",
+    "js\examples\Border",
+    "js\examples\Button",
+    "js\examples\ContentURLAndroid",
+    "js\examples\Crash",
+    "js\examples\DevSettings",
+    "js\examples\Dimensions",
+    "js\examples\DisplayContents",
+    "js\examples\DrawerLayoutAndroid",
+    "js\examples\Experimental",
+    "js\examples\Filter",
+    "js\examples\FlatList",
+    "js\examples\Image",
+    "js\examples\InputAccessoryView",
+    "js\examples\InvalidProps",
+    "js\examples\JSResponderHandlerExample",
+    "js\examples\Keyboard",
+    "js\examples\KeyboardAvoidingView",
+    "js\examples\Layout",
+    "js\examples\LinearGradient",
+    "js\examples\MixBlendMode",
+    "js\examples\Modal",
+    "js\examples\NativeAnimation",
+    "js\examples\NewAppScreen",
+    "js\examples\NewArchitecture",
+    "js\examples\OrientationChange",
+    "js\examples\OSSLibraryExample",
+    "js\examples\PanResponder",
+    "js\examples\Performance",
+    "js\examples\PermissionsAndroid",
+    "js\examples\PixelRatio",
+    "js\examples\PlatformColor",
+    "js\examples\Playground",
+    "js\examples\PointerEvents",
+    "js\examples\PopupMenuAndroid",
+    "js\examples\Pressable",
+    "js\examples\RCTRootView",
+    "js\examples\RootViewSizeFlexibilityExample",
+    "js\examples\RTL",
+    "js\examples\ScrollView",
+    "js\examples\SectionList",
+    "js\examples\SetPropertiesExample",
+    "js\examples\Share",
+    "js\examples\Snapshot",
+    "js\examples\StatusBar",
+    "js\examples\Switch",
+    "js\examples\Text",
+    "js\examples\Timer",
+    "js\examples\ToastAndroid",
+    "js\examples\Touchable",
+    "js\examples\Transform",
+    "js\examples\TransparentHitTest",
+    "js\examples\TurboModule",
+    "js\examples\Vibration",
+    "js\examples\View",
+    "js\examples\XHR",
+    "js\types"
+)
+
+# Determine operation mode
+$Mode = "RNTester Override Directories + IntegrationTests"
+
+# Show help if requested
+if ($args -contains "--help" -or $args -contains "-h") {
+    Show-Help
+    exit 0
+}
+
+Write-Info "=== RNTester Sync Script ==="
+Write-Info "Auto-detected paths:"
+Write-Info "  Windows Repo: $WindowsRepoRoot"
+Write-Info "  Tester Path:  $TesterPath"
+Write-Info "  Integration Tests: $IntegrationTestsPath"
+Write-Info "  Cache Dir:    $CacheDir"
+Write-Info "Mode: $Mode"
+Write-Info "Commit: $CommitHash"
+if ($DryRun) { Write-Warning "DRY RUN MODE - No files will be modified" }
+
+# Check if git is available
+if (-not (Get-Command git -ErrorAction SilentlyContinue)) {
+    Write-Error "Git is not installed or not in PATH"
+    exit 1
+}
+
+# Setup repository cache
+$RepoDir = Join-Path $CacheDir "react-native"
+$UpdatedFiles = @()
+$FailedFiles = @()
+
+try {
+    # Create cache directory if it doesn't exist
+    if (-not (Test-Path $CacheDir)) {
+        Write-Info "Creating cache directory: $CacheDir"
+        New-Item -ItemType Directory -Path $CacheDir -Force | Out-Null
+    }
+
+    # Check if repo already exists
+    if ((Test-Path $RepoDir) -and (-not $ForceClone)) {
+        Write-Info "Using cached React Native repository at: $RepoDir"
+        Set-Location $RepoDir
+        
+        # Fetch latest changes
+        Write-Info "Fetching latest changes..."
+        git fetch origin 2>&1 | Out-Host
+        
+        # Check if commit exists locally
+        $CommitExists = git rev-parse --verify "$CommitHash^{commit}" 2>$null
+        if ($LASTEXITCODE -ne 0) {
+            Write-Warning "Commit $CommitHash not found locally, fetching more history..."
+            git fetch --depth 1000 origin 2>&1 | Out-Host
+        }
+    } else {
+        if (Test-Path $RepoDir) {
+            Write-Warning "Removing existing repository (ForceClone=$ForceClone)"
+            Remove-Item $RepoDir -Recurse -Force
+        }
+        
+        Write-Info "Cloning React Native repository to cache..."
+        git clone --depth 500 $ReactNativeRepo $RepoDir 2>&1 | Out-Host
+        if ($LASTEXITCODE -ne 0) {
+            throw "Failed to clone React Native repository"
+        }
+        Set-Location $RepoDir
+    }
+
+    # Checkout the specific commit
+    Write-Info "Checking out commit $CommitHash..."
+    git checkout $CommitHash --quiet 2>$null
+    if ($LASTEXITCODE -ne 0) {
+        Write-Warning "Failed to checkout $CommitHash, trying deeper fetch..."
+        git fetch --depth 2000 origin 2>&1 | Out-Host
+        git checkout $CommitHash --quiet 2>$null
+        if ($LASTEXITCODE -ne 0) {
+            throw "Failed to checkout commit $CommitHash even after deeper fetch"
+        }
+    }
+
+    # Show commit info
+    $CommitInfo = git log -1 --oneline $CommitHash
+    Write-Success "Using commit: $CommitInfo"
+
+    $UpstreamTesterPath = Join-Path $RepoDir "packages\rn-tester"
+    if (-not (Test-Path $UpstreamTesterPath)) {
+        throw "Upstream rn-tester directory not found at: $UpstreamTesterPath"
+    }
+
+    # Sync RNTester override directories
+    Write-Info "Processing $($OverrideDirectories.Count) override directories..."
+
+    foreach ($RelativeDir in $OverrideDirectories) {
+            $SourceDir = Join-Path $UpstreamTesterPath $RelativeDir
+            $TargetDir = Join-Path $TesterPath $RelativeDir
+            
+            Write-Info "Processing: $RelativeDir"
+
+            if (-not (Test-Path $SourceDir)) {
+                Write-Warning "Source directory not found: $RelativeDir (skipping)"
+                continue
+            }
+
+            if (-not (Test-Path $TargetDir)) {
+                if (-not $DryRun) {
+                    New-Item -ItemType Directory -Path $TargetDir -Force | Out-Null
+                    Write-Info "Created directory: $TargetDir"
+                } else {
+                    Write-Info "[DRY RUN] Would create directory: $TargetDir"
+                }
+            }
+
+            $SourceFiles = Get-ChildItem -Path $SourceDir -Recurse -File
+            foreach ($SourceFile in $SourceFiles) {
+                $RelativeFilePath = $SourceFile.FullName.Substring($SourceDir.Length + 1)
+                $TargetFile = Join-Path $TargetDir $RelativeFilePath
+                $TargetFileDir = Split-Path $TargetFile -Parent
+
+                if (-not (Test-Path $TargetFileDir)) {
+                    if (-not $DryRun) {
+                        New-Item -ItemType Directory -Path $TargetFileDir -Force | Out-Null
+                    } else {
+                        Write-Info "[DRY RUN] Would create directory: $TargetFileDir"
+                    }
+                }
+
+                try {
+                    if (-not $DryRun) {
+                        Copy-Item -Path $SourceFile.FullName -Destination $TargetFile -Force
+                        $UpdatedFiles += $TargetFile
+                        Write-Success "Updated: $($RelativeDir)\$($RelativeFilePath)"
+                    } else {
+                        Write-Info "[DRY RUN] Would update: $($RelativeDir)\$($RelativeFilePath)"
+                    }
+                } catch {
+                    Write-Error "Failed to copy $($RelativeDir)\$($RelativeFilePath)`: $_"
+                    $FailedFiles += "$($RelativeDir)\$($RelativeFilePath)"
+                }
+            }
+
+            # Remove obsolete files
+            if (Test-Path $TargetDir) {
+                $TargetFiles = Get-ChildItem -Path $TargetDir -Recurse -File
+                foreach ($TargetFile in $TargetFiles) {
+                    $RelativeFilePath = $TargetFile.FullName.Substring($TargetDir.Length + 1)
+                    $SourceFile = Join-Path $SourceDir $RelativeFilePath
+                    
+                    if (-not (Test-Path $SourceFile)) {
+                        if (-not $DryRun) {
+                            Remove-Item -Path $TargetFile.FullName -Force
+                            Write-Warning "Removed obsolete file: $($RelativeDir)\$($RelativeFilePath)"
+                        } else {
+                            Write-Info "[DRY RUN] Would remove obsolete file: $($RelativeDir)\$($RelativeFilePath)"
+                        }
+                    }
+                }
+            }
+        }
+
+    # Sync IntegrationTests
+    Write-Info "Syncing IntegrationTests directory..."
+    
+    $SourceIntegrationTestsDir = Join-Path $RepoDir "packages\rn-tester\IntegrationTests"
+    
+    if (Test-Path $SourceIntegrationTestsDir) {
+        # Create target directory if it doesn't exist
+        if (-not (Test-Path $IntegrationTestsPath)) {
+            if (-not $DryRun) {
+                New-Item -ItemType Directory -Path $IntegrationTestsPath -Force | Out-Null
+                Write-Info "Created IntegrationTests directory: $IntegrationTestsPath"
+            } else {
+                Write-Info "[DRY RUN] Would create directory: $IntegrationTestsPath"
+            }
+        }
+        
+        # Get all files in source IntegrationTests directory
+        $IntegrationSourceFiles = Get-ChildItem -Path $SourceIntegrationTestsDir -Recurse -File
+        
+        foreach ($SourceFile in $IntegrationSourceFiles) {
+            $RelativeFilePath = $SourceFile.FullName.Substring($SourceIntegrationTestsDir.Length + 1)
+            $TargetFile = Join-Path $IntegrationTestsPath $RelativeFilePath
+            $TargetFileDir = Split-Path $TargetFile -Parent
+
+            if (-not (Test-Path $TargetFileDir)) {
+                if (-not $DryRun) {
+                    New-Item -ItemType Directory -Path $TargetFileDir -Force | Out-Null
+                } else {
+                    Write-Info "[DRY RUN] Would create directory: $TargetFileDir"
+                }
+            }
+
+            try {
+                if (-not $DryRun) {
+                    Copy-Item -Path $SourceFile.FullName -Destination $TargetFile -Force
+                    $UpdatedFiles += $TargetFile
+                    Write-Success "Updated IntegrationTests: $RelativeFilePath"
+                } else {
+                    Write-Info "[DRY RUN] Would update IntegrationTests: $RelativeFilePath"
+                }
+            } catch {
+                Write-Error "Failed to copy IntegrationTests file $RelativeFilePath`: $_"
+                $FailedFiles += "IntegrationTests\$RelativeFilePath"
+            }
+        }
+        
+        # Remove obsolete files in IntegrationTests
+        if (Test-Path $IntegrationTestsPath) {
+            $TargetIntegrationFiles = Get-ChildItem -Path $IntegrationTestsPath -Recurse -File
+            foreach ($TargetFile in $TargetIntegrationFiles) {
+                $RelativeFilePath = $TargetFile.FullName.Substring($IntegrationTestsPath.Length + 1)
+                $SourceFile = Join-Path $SourceIntegrationTestsDir $RelativeFilePath
+                
+                if (-not (Test-Path $SourceFile)) {
+                    if (-not $DryRun) {
+                        Remove-Item -Path $TargetFile.FullName -Force
+                        Write-Warning "Removed obsolete IntegrationTests file: $RelativeFilePath"
+                    } else {
+                        Write-Info "[DRY RUN] Would remove obsolete IntegrationTests file: $RelativeFilePath"
+                    }
+                }
+            }
+        }
+    } else {
+        Write-Warning "IntegrationTests directory not found in upstream commit: $SourceIntegrationTestsDir"
+    }
+
+} catch {
+    Write-Error "Error: $_"
+    exit 1
+} finally {
+    Write-Info "Repository cached at: $RepoDir"
+}
+
+# Summary
+Write-Info "`n=== SUMMARY ==="
+Write-Info "Mode: $Mode"
+Write-Info "Commit: $CommitHash"
+Write-Success "Updated files: $($UpdatedFiles.Count)"
+if ($FailedFiles.Count -gt 0) {
+    Write-Error "Failed files: $($FailedFiles.Count)"
+    $FailedFiles | ForEach-Object { Write-Host "  - $_" -ForegroundColor Red }
+}
+
+if (-not $DryRun) {
+    Write-Success "`nRNTester and IntegrationTests synced!"
+} else {
+    Write-Info "`n[DRY RUN] Use without -DryRun to actually perform the sync."
+}
\ No newline at end of file