diff --git a/Tools/PRTest.ps1 b/Tools/PRTest.ps1
index fc5bbf7cb3529..68a4401a08d31 100644
--- a/Tools/PRTest.ps1
+++ b/Tools/PRTest.ps1
@@ -1,11 +1,22 @@
-# This script does a checkout of a Pull Request using the GitHub CLI, and then runs it using SandboxTest.ps1.
+### Exit Codes:
+#  0 = Success
+#  1 = Missing dependency
+#  2 = Pull request checkout error
+#  3 = Validation completed check was not found
+#  4 = Artifact download URL was not found
+#  5 = YAML manifest was not found
+###
+
+# This script checks out a Pull Request or downloads its validated merged manifest,
+# and then runs it using SandboxTest.ps1.
 
 Param(
-    [Parameter(Position = 0, HelpMessage = 'The Pull Request to checkout.', Mandatory = $true)]
+    [Parameter(Position = 0, HelpMessage = 'The Pull Request to test.', Mandatory = $true)]
     [String] $PullRequest,
     [Parameter(HelpMessage = "Open the Pull Request's review page in the default browser")]
     [Switch] $Review = $false,
     [Switch] $KeepBranch = $false,
+    [Switch] $NoCheckout = $false,
     [Switch] $Prerelease = $false,
     [Switch] $EnableExperimentalFeatures = $false,
     [string] $WinGetVersion = $null,
@@ -23,6 +34,18 @@ filter Initialize-VirtualTerminalSequence {
     }
 }
 
+function Write-PRTestError {
+    param(
+        [Parameter(Mandatory = $true)]
+        [string] $Message,
+        [Parameter(Mandatory = $true)]
+        [int] $ExitCode
+    )
+
+    Write-Error -Message $Message -ErrorAction Continue
+    exit $ExitCode
+}
+
 # Flags
 Write-Debug 'Checking for supported features'
 $script:vtSupported = (Get-Host).UI.SupportsVirtualTerminal
@@ -37,21 +60,86 @@ $script:vtForegroundGreen = 32 | Initialize-VirtualTerminalSequence
 Write-Debug 'Creating internal state'
 $PullRequest = $PullRequest.TrimStart('#')
 $ErrorActionPreference = 'Stop'
-$repositoryRoot = 'https://github.com/microsoft/winget-pkgs/'
-$rootDirectory = ((Resolve-Path (git rev-parse --show-toplevel)).ToString() + '\')
+$repository = 'microsoft/winget-pkgs'
 
 Write-Verbose 'Ensuring Dependencies are Present'
-if (!$script:GhIsPresent) { Write-Error "The GitHub CLI is not installed. Install it via 'winget install GitHub.cli' and come back here!" -ErrorAction Stop }
-if (!$script:GitIsPresent) { Write-Error "Git is not installed. Install it via 'winget install Git.Git' and come back here!" -ErrorAction Stop }
-if (!$script:SandboxIsPresent) { Write-Error 'Windows Sandbox is not enabled. Enable it and come back here!' -ErrorAction Stop }
+if (!$script:GhIsPresent) { Write-PRTestError "The GitHub CLI is not installed. Install it via 'winget install GitHub.cli' and come back here!" 1 }
+if (!$NoCheckout -and !$script:GitIsPresent) { Write-PRTestError "Git is not installed. Install it via 'winget install Git.Git' and come back here!" 1 }
+if (!$script:SandboxIsPresent) { Write-PRTestError 'Windows Sandbox is not enabled. Enable it and come back here!' 1 }
+
+if ($NoCheckout) {
+    $rootFolder = Join-Path $env:TEMP 'WinGet-PRTest'
+    if ($Clean -and (Test-Path $rootFolder)) { Remove-Item $rootFolder -Recurse -Force }
+
+    Write-Output '--> Retrieving PR check runs'
+    $headSha = gh api "repos/$repository/pulls/$PullRequest" --jq '.head.sha'
+    $checkRuns = gh api "repos/$repository/commits/$headSha/check-runs?app_id=1451866&filter=latest&per_page=100" |
+        ConvertFrom-Json -ErrorAction SilentlyContinue
+    $validationCompletedCheck = $checkRuns.check_runs |
+        Where-Object {
+            $_.name -eq '10. Validation Completed' -and
+            $_.app.slug -eq 'wingetvalidator-prod' -and
+            $_.head_sha -eq $headSha -and
+            $_.status -eq 'completed'
+        } |
+        Select-Object -First 1
+
+    if (!$validationCompletedCheck) {
+        Write-PRTestError "The check run was not found for PR #$PullRequest." 3
+    }
+
+    $json = [regex]::Match(
+        [string] $validationCompletedCheck.output.text,
+        '(?ms)```json\s*(?<json>.*?)\s*```'
+    ).Groups['json'].Value
+    $artifactDownloadUrl = ($json | ConvertFrom-Json -ErrorAction SilentlyContinue).Artifacts.ArtifactDownloadUrl
+    if ([string]::IsNullOrWhiteSpace($artifactDownloadUrl)) {
+        Write-PRTestError "The artifact download URL was not found for PR #$PullRequest." 4
+    }
 
-Write-Verbose 'Checking out PR'
-gh pr checkout $PullRequest $(if (!$KeepBranch) { '--detach' }) -f -R $repositoryRoot | Out-Null
-if ($LASTEXITCODE -ne 0) { Write-Error "There was an error checking out the PR. Make sure you're logged into GitHub via 'gh auth login' and come back here!" -ErrorAction Stop }
+    $runFolder = Join-Path $rootFolder "$PullRequest\$headSha"
+    $zipPath = Join-Path $runFolder 'artifacts.zip'
+    $manifestFolder = Join-Path $runFolder 'Manifest'
+    if (Test-Path $runFolder) { Remove-Item $runFolder -Recurse -Force }
+    New-Item $manifestFolder -ItemType Directory | Out-Null
 
-Write-Verbose 'Parsing changed files'
-$manifest = @(gh pr diff $PullRequest --name-only)
-$path = (Get-Item (Resolve-Path ($rootDirectory + $manifest[0]))).Directory
+    Write-Output '--> Downloading validation artifact'
+    Invoke-WebRequest $artifactDownloadUrl -OutFile $zipPath
+
+    # Only extract the YAML manifest entry from the archive; the artifact also contains
+    # installation verification logs whose long, nested paths can fail to extract.
+    $manifestFile = $null
+    try {
+        $zipArchive = [System.IO.Compression.ZipFile]::OpenRead($zipPath)
+        $yamlEntries = @($zipArchive.Entries | Where-Object { $_.Name -like '*.yaml' })
+        if ($yamlEntries.Count -eq 1) {
+            Write-Output "--> Extracting file: $($yamlEntries[0].Name)"
+            $manifestFile = Join-Path $manifestFolder $yamlEntries[0].Name
+            [System.IO.Compression.ZipFileExtensions]::ExtractToFile($yamlEntries[0], $manifestFile)
+        }
+    } finally {
+        if ($zipArchive) { $zipArchive.Dispose() }
+    }
+
+    if (!$manifestFile -or !(Test-Path $manifestFile -PathType Leaf)) {
+        Write-PRTestError "A single YAML manifest was not found in the validation artifact for PR #$PullRequest." 5
+    }
+
+    $path = $manifestFolder
+} else {
+    $repositoryRoot = 'https://github.com/microsoft/winget-pkgs/'
+    $rootDirectory = ((Resolve-Path (git rev-parse --show-toplevel)).ToString() + '\')
+
+    Write-Verbose 'Checking out PR'
+    gh pr checkout $PullRequest $(if (!$KeepBranch) { '--detach' }) -f -R $repositoryRoot | Out-Null
+    if ($LASTEXITCODE -ne 0) {
+        Write-PRTestError "There was an error checking out the PR. Make sure you're logged into GitHub via 'gh auth login' and come back here!" 2
+    }
+
+    Write-Verbose 'Parsing changed files'
+    $manifest = @(gh pr diff $PullRequest --name-only)
+    $path = (Get-Item (Resolve-Path ($rootDirectory + $manifest[0]))).Directory
+}
 
 Write-Verbose 'Passing execution to SandboxTest.ps1'
 $sandboxTestPath = (Resolve-Path ($PSScriptRoot.ToString() + '\SandboxTest.ps1')).ToString()