diff --git a/.github/workflows/_spm.yml b/.github/workflows/_spm.yml
index 179caa899ff..8156402aa98 100644
--- a/.github/workflows/_spm.yml
+++ b/.github/workflows/_spm.yml
@@ -61,6 +61,12 @@ on:
         required: false
         default: false
 
+      # Whether to test Xcode 27. Defaults to false.
+      test_xcode27:
+        type: boolean
+        required: false
+        default: false
+
       # Custom environment variables to inject into the jobs.
       # Expected to be a JSON-formatted string.
       # Example: '{"FIREBASE_APP_CHECK_BRANCH": "nc/target-split"}'
@@ -126,14 +132,23 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-15, macos-26]
-        xcode: [Xcode_26.2, Xcode_26.4]
+        os: [macos-15, macos-26, xcode-27]
+        xcode: [Xcode_26.2, Xcode_26.4, Xcode_27.0]
         platform: [iOS, tvOS, macOS, watchOS, catalyst, visionOS]
         exclude:
           - os: macos-15
             xcode: Xcode_26.4
+          - os: macos-15
+            xcode: Xcode_27.0
+          - os: macos-26
+            xcode: Xcode_26.2
           - os: macos-26
+            xcode: Xcode_27.0
+          - os: xcode-27
             xcode: Xcode_26.2
+          - os: xcode-27
+            xcode: Xcode_26.4
+          - xcode: ${{ !inputs.test_xcode27 && 'Xcode_27.0' || 'none' }}
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
diff --git a/.github/workflows/infra.samples.client_app.yml b/.github/workflows/infra.samples.client_app.yml
index d453fd1eada..18656e013dc 100644
--- a/.github/workflows/infra.samples.client_app.yml
+++ b/.github/workflows/infra.samples.client_app.yml
@@ -33,10 +33,12 @@ jobs:
         #TODO(ncooke3): Add multi-platform support: tvOS, macOS, catalyst
         platform: [iOS]
         scheme: [ClientApp]
-        os: [macos-15]
+        os: [macos-15, xcode-27]
         include:
           - os: macos-15
             xcode: Xcode_26.2
+          - os: xcode-27
+            xcode: Xcode_27.0
     uses: ./.github/workflows/_build.yml
     with:
       product: ${{ matrix.scheme }}
@@ -51,10 +53,12 @@ jobs:
         #TODO(ncooke3): Add multi-platform support: tvOS, macOS, catalyst
         platform: [iOS]
         scheme: [ClientApp]
-        os: [macos-15]
+        os: [macos-15, xcode-27]
         include:
           - os: macos-15
             xcode: Xcode_26.2
+          - os: xcode-27
+            xcode: Xcode_27.0
     uses: ./.github/workflows/_build.yml
     with:
       product: ${{ matrix.scheme }}
diff --git a/.github/workflows/sdk.ai.yml b/.github/workflows/sdk.ai.yml
index 43d8e875566..4f682a66f17 100644
--- a/.github/workflows/sdk.ai.yml
+++ b/.github/workflows/sdk.ai.yml
@@ -33,6 +33,7 @@ jobs:
     uses: ./.github/workflows/_spm.yml
     with:
       target: ${{  matrix.target }}
+      test_xcode27: true
       setup_command: scripts/update_vertexai_responses.sh
       env_vars: '{"FIREBASE_APP_CHECK_BRANCH": "main"}'
 
@@ -63,6 +64,11 @@ jobs:
             xcode: Xcode_26.2
             test_filter_arg: --filter IntegrationTests-SPM/LiveSessionTests
             log_prefix: xcodebuild-live
+          - os: xcode-27
+            target: iOS
+            xcode: Xcode_27.0
+            test_filter_arg: --exclude IntegrationTests-SPM/LiveSessionTests
+            log_prefix: xcodebuild
     runs-on: ${{ matrix.os }}
     needs: spm
     env:
@@ -109,6 +115,8 @@ jobs:
           # TODO: Bump to 26.4 when "Unable to find a destination matching the provided destination specifier" is resolved.
           - os: macos-26
             xcode: Xcode_26.2
+          - os: xcode-27
+            xcode: Xcode_27.0
     runs-on: ${{ matrix.os }}
     env:
       BRANCH_NAME: ${{ github.head_ref || github.ref_name || 'main' }}
diff --git a/.github/workflows/sdk.auth.yml b/.github/workflows/sdk.auth.yml
index 129d2ea2205..1e06d281b60 100644
--- a/.github/workflows/sdk.auth.yml
+++ b/.github/workflows/sdk.auth.yml
@@ -33,6 +33,7 @@ jobs:
     uses: ./.github/workflows/_spm.yml
     with:
       target: AuthUnit
+      test_xcode27: true
       buildonly_platforms: macOS
 
   catalyst:
diff --git a/.github/workflows/sdk.firestore.yml b/.github/workflows/sdk.firestore.yml
index 54b9a9addd9..528f1da1ec4 100644
--- a/.github/workflows/sdk.firestore.yml
+++ b/.github/workflows/sdk.firestore.yml
@@ -637,6 +637,7 @@ jobs:
     uses: ./.github/workflows/_spm.yml
     with:
       target: FirebaseFirestoreTests
+      test_xcode27: true
       platforms: iOS
 
   spm-source-cron: