diff --git a/.github/workflows/android.yml b/.github/workflows/android.yml
index cdd35932d..85c083b61 100644
--- a/.github/workflows/android.yml
+++ b/.github/workflows/android.yml
@@ -13,7 +13,7 @@ on:
 env:
   CCACHE_DIR: ${{ github.workspace }}/ccache_dir
   GITHUB_TOKEN: ${{ github.token }}
-  xcodeVersion: "14.1"  # Only affects Mac runners, and only for prerequisites.
+  xcodeVersion: "16.2"  # Only affects Mac runners, and only for prerequisites.
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.event_name }}-${{ github.head_ref || github.ref }}
@@ -50,6 +50,15 @@ jobs:
         os: ${{ fromJson(needs.prepare_matrix.outputs.matrix_os) }}
         architecture: ${{ fromJson(needs.prepare_matrix.outputs.matrix_architecture) }}
         python_version: ${{ fromJson(needs.prepare_matrix.outputs.matrix_python_version) }}
+        exclude:
+        # Do not attempt to use arm64 on Windows or Linux.
+        - os: windows-latest
+          architecture: arm64
+        - os: ubuntu-22.04
+          architecture: arm64
+        # Do not attempt to use x64 on Mac.
+        - os: macos-14
+          architecture: x64
     steps:
       - uses: lukka/get-cmake@latest
         with:
@@ -58,8 +67,13 @@ jobs:
         if: runner.os == 'macOS'
         run: sudo xcode-select -s /Applications/Xcode_${{ env.xcodeVersion }}.app/Contents/Developer
       - name: Force Java 11
+        if: runner.os != 'macOS'
         shell: bash
         run: echo "JAVA_HOME=${JAVA_HOME_11_X64}" >> $GITHUB_ENV
+      - name: Force Java 11 (mac)
+        if: runner.os == 'macOS'
+        shell: bash
+        run: echo "JAVA_HOME=${JAVA_HOME_11_arm64}" >> $GITHUB_ENV
       - name: Store git credentials for all git commands
         # Forces all git commands to use authenticated https, to prevent throttling.
         shell: bash
diff --git a/.github/workflows/cpp-packaging.yml b/.github/workflows/cpp-packaging.yml
index 525062c49..d31257572 100644
--- a/.github/workflows/cpp-packaging.yml
+++ b/.github/workflows/cpp-packaging.yml
@@ -32,9 +32,9 @@ env:
   demumbleVer: "df938e45c2b0e064fb5323d88b692d03b451d271"
   # Use SHA256 for hashing files.
   hashCommand: "sha256sum"
-  # Xcode version 15.1 is the version we build the SDK with.
+  # Xcode version 16.2 is the version we build the SDK with.
   # Our MacOS runners will use the version in /Applications/Xcode_${xcodeVersion}.app
-  xcodeVersion: "15.1"
+  xcodeVersion: "16.2"
   # LLVM version with ARM MachO support has no version number yet.
   llvmVer: "5f187f0afaad33013ba03454c4749d99b1362534"
   GITHUB_TOKEN: ${{ github.token }}
@@ -79,13 +79,13 @@ jobs:
     if: ${{ github.event.inputs.downloadPublicVersion == '' && github.event.inputs.downloadPreviousRun == '' }}
     strategy:
       matrix:
-        os: [ubuntu-22.04, macos-13]
+        os: [ubuntu-22.04, macos-14]
         include:
         - os: ubuntu-22.04
           tools_platform: linux
           # Binutils 2.35.1 released Sep 19, 2020
           binutils_version: "2.35.1"
-        - os: macos-13
+        - os: macos-14
           tools_platform: darwin
           # Binutils 2.35.1 released Sep 19, 2020
           binutils_version: "2.35.1"
@@ -188,7 +188,7 @@ jobs:
 
   build_and_package_ios_tvos:
     name: build-and-package-ios-tvos
-    runs-on: macos-13
+    runs-on: macos-14
     if: ${{ github.event.inputs.downloadPublicVersion == '' && github.event.inputs.downloadPreviousRun == '' }}
     steps:
       - uses: lukka/get-cmake@latest
@@ -317,7 +317,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [windows-latest, ubuntu-22.04, macos-13]
+        os: [windows-latest, ubuntu-22.04, macos-14]
         build_type: ["Release", "Debug"]
         architecture: ["x64", "x86", "arm64"]
         msvc_runtime: ["static", "dynamic"]
@@ -335,7 +335,7 @@ jobs:
           vcpkg_triplet_suffix: "linux"
           additional_build_flags: ""
           sdk_platform: "linux"
-        - os: macos-13
+        - os: macos-14
           vcpkg_triplet_suffix: "osx"
           additional_build_flags: "--target_format libraries"
           sdk_platform: "darwin"
@@ -343,13 +343,13 @@ jobs:
         exclude:
         - os: windows-latest
           linux_abi: "c++11"
-        - os: macos-13
+        - os: macos-14
           architecture: "x86"
-        - os: macos-13
+        - os: macos-14
           msvc_runtime: "dynamic"
-        - os: macos-13
+        - os: macos-14
           linux_abi: "c++11"
-        - os: macos-13
+        - os: macos-14
           build_type: "Debug"
         - os: ubuntu-22.04
           msvc_runtime: "dynamic"
@@ -504,7 +504,7 @@ jobs:
           suffix: '-x64-Debug-dynamic'
           runs_on_platform: ubuntu-22.04
         - sdk_platform: darwin
-          runs_on_platform: macos-13
+          runs_on_platform: macos-14
         exclude:
         - sdk_platform: windows
           suffix: ''
diff --git a/.github/workflows/desktop.yml b/.github/workflows/desktop.yml
index 36754a136..5aad61c38 100644
--- a/.github/workflows/desktop.yml
+++ b/.github/workflows/desktop.yml
@@ -72,11 +72,13 @@ jobs:
           # msvc_runtime excludes
           - os: ubuntu-22.04
             msvc_runtime: "dynamic"
-          - os: macos-13
+          - os: macos-14
             msvc_runtime: "dynamic"
           # architecture excluees
-          - os: macos-13
+          - os: macos-14
             architecture: "x86"
+          - os: macos-14
+            architecture: "x64"
           # Xcode excludes -- allow only one on osx and linux
           - os: ubuntu-22.04
             xcode_version: "11.7"
@@ -168,9 +170,17 @@ jobs:
 
       - name: Setup python
         uses: actions/setup-python@v4
+        if: startsWith(matrix.os, 'ubuntu')
+        with:
+          python-version: ${{ matrix.python_version }}
+          architecture: x64
+
+      - name: Setup python (Mac)
+        uses: actions/setup-python@v4
+        if: startsWith(matrix.os, 'macos')
         with:
           python-version: ${{ matrix.python_version }}
-          architecture: 'x64'
+          architecture: ${{ matrix.architecture }}
 
       - name: Install Desktop SDK prerequisites
         uses: nick-invision/retry@v2
diff --git a/.github/workflows/integration_tests.yml b/.github/workflows/integration_tests.yml
index ebf18b5d2..68a8eaefd 100644
--- a/.github/workflows/integration_tests.yml
+++ b/.github/workflows/integration_tests.yml
@@ -21,7 +21,7 @@ on:
         required: true
       operating_systems:
         description: 'CSV of VMs to run on'
-        default: 'ubuntu-22.04,windows-latest,macos-13'
+        default: 'ubuntu-22.04,windows-latest,macos-14'
         required: true
       desktop_ssl_variants:
         description: 'CSV of desktop SSL variants to use'
@@ -49,14 +49,9 @@ env:
   triggerLabelFull: "tests-requested: full"
   triggerLabelQuick: "tests-requested: quick"
   pythonVersion: '3.8'
-  xcodeVersion: '15.1'
+  xcodeVersion: '16.2'
   artifactRetentionDays: 2
   GITHUB_TOKEN: ${{ github.token }}
-  # All self-hosted ARM Mac runners should have this label. Due to how
-  # our custom reporting works, it must be exactly two words separated
-  # by a hyphen. The first word must be "macos". The second word will
-  # be omitted from the summary log.
-  runnerLabelMacArm64: "macos-m1custom"
 
 jobs:
   check_and_prepare:
@@ -77,8 +72,6 @@ jobs:
       xcode_version: ${{ steps.matrix_config.outputs.xcode_version }}
       ios_device: ${{ steps.matrix_config.outputs.ios_device }}
       tvos_device: ${{ steps.matrix_config.outputs.tvos_device }}
-      # Copy the runner label here because matrix specifiers cannot see env.
-      runner_label_macos_arm64: ${{ env.runnerLabelMacArm64 }}
     steps:
     ### Fail the workflow if the user does not have admin access to run the tests.
     - name: Check if user has permission to trigger tests
@@ -206,7 +199,7 @@ jobs:
           # at 3am PST/4am PDT. Running firestore desktop integration test aginst tip-of-tree ios repo
           echo "::warning ::Running against Firestore tip-of-tree"
           matrix_platform="Desktop"
-          matrix_os=$( python scripts/gha/print_matrix_configuration.py -w integration_tests ${TEST_MATRIX_PARAM} -k os -o "ubuntu-22.04,macos-13")
+          matrix_os=$( python scripts/gha/print_matrix_configuration.py -w integration_tests ${TEST_MATRIX_PARAM} -k os -o "ubuntu-22.04,macos-14")
         else
           matrix_platform=$( python scripts/gha/print_matrix_configuration.py -w integration_tests ${TEST_MATRIX_PARAM} -k platform -o "${{github.event.inputs.platforms}}" --apis ${apis} )
           matrix_os=$( python scripts/gha/print_matrix_configuration.py -w integration_tests ${TEST_MATRIX_PARAM} -k os -o "${{github.event.inputs.operating_systems}}")
@@ -273,18 +266,18 @@ jobs:
         - os: ubuntu-22.04
           arch: arm64
         # Do not attempt to use x86 on Mac.
-        - os: macos-13
+        - os: macos-14
           arch: x86
         # Until we support building openssl from source, we can't use the
-        # system's openssl when cross-compiling, except on Linux. Builds all
-        # happen on x64 machines, so arm64 and x86 are technically
-        # cross-compiling.
+        # system's openssl when cross-compiling, except on Linux. Builds on Linux
+        # happen on x64 machines, so x86 is technically cross-compiling. Builds on
+        # Mac happen on arm64 machines, so x64 is technically cross-compiling.
         - os: windows-latest
           ssl_variant: openssl
           arch: x86
-        - os: macos-13
+        - os: macos-14
           ssl_variant: openssl
-          arch: arm64
+          arch: x64
     steps:
       - uses: lukka/get-cmake@latest
         with:
@@ -435,8 +428,13 @@ jobs:
           ref: ${{needs.check_and_prepare.outputs.github_ref}}
           submodules: true
       - name: Force Java 11
+        if: ${{ !(runner.os == 'macOS') }}
         shell: bash
         run: echo "JAVA_HOME=${JAVA_HOME_11_X64}" >> $GITHUB_ENV
+      - name: Force Java 11 (mac)
+        if: ${{ runner.os == 'macOS' }}
+        shell: bash
+        run: echo "JAVA_HOME=${JAVA_HOME_11_arm64}" >> $GITHUB_ENV
       - name: Add msbuild to PATH (Windows)
         if: startsWith(matrix.os, 'windows')
         uses: microsoft/setup-msbuild@v1.1
@@ -539,7 +537,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-13]
+        os: [macos-14]
     steps:
       - uses: lukka/get-cmake@latest
         with:
@@ -647,7 +645,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [macos-13]
+        os: [macos-14]
     steps:
       - uses: lukka/get-cmake@latest
         with:
@@ -767,20 +765,18 @@ jobs:
         - os: ubuntu-22.04
           arch: arm64
         # Do not attempt to use x86 on Mac.
-        - os: macos-13
+        - os: macos-14
           arch: x86
         # Until we support building openssl from source, we can't use the
-        # system's openssl when cross-compiling, except on Linux. Builds all
-        # happen on x64 machines, so arm64 and x86 are technically
-        # cross-compiling.
+        # system's openssl when cross-compiling, except on Linux. Builds on Linux
+        # happen on x64 machines, so x86 is technically cross-compiling. Builds on
+        # Mac happen on arm64 machines, so x64 is technically cross-compiling.
         - os: windows-latest
           ssl_variant: openssl
           arch: x86
-        # Custom for this matrix: MacOS GitHub-hosted runner cannot test arm64
-        # code. Exclude that scenario from running here; it will run in
-        # test_desktop_custom_runners.
-        - os: macos-13
-          arch: arm64
+        - os: macos-14
+          ssl_variant: openssl
+          arch: x64
     steps:
       - uses: actions/checkout@v3
         with:
@@ -1010,7 +1006,7 @@ jobs:
   test_ios:
     name: test-ios-${{ matrix.build_os }}-${{ matrix.ios_device }}-${{ matrix.test_type }}
     needs: [check_and_prepare, build_ios]
-    runs-on: macos-13
+    runs-on: macos-14
     if: contains(needs.check_and_prepare.outputs.matrix_platform, 'iOS') && needs.check_and_prepare.outputs.apis != '' && !cancelled()
     strategy:
       fail-fast: false
@@ -1024,7 +1020,7 @@ jobs:
              test_type: "uitest"
           -  ios_device: "ios_latest"
              test_type: "uitest"
-        build_os: [macos-13]
+        build_os: [macos-14]
     steps:
       - uses: actions/checkout@v3
         with:
@@ -1189,13 +1185,13 @@ jobs:
   test_tvos:
     name: test-tvos-${{ matrix.build_os }}-${{ matrix.tvos_device }}
     needs: [check_and_prepare, build_tvos]
-    runs-on: macos-13
+    runs-on: macos-14
     if: contains(needs.check_and_prepare.outputs.matrix_platform, 'tvOS') && needs.check_and_prepare.outputs.apis != '' && !cancelled()
     strategy:
       fail-fast: false
       matrix:
         tvos_device: ${{ fromJson(needs.check_and_prepare.outputs.tvos_device) }}
-        build_os: [macos-13]
+        build_os: [macos-14]
     steps:
       - uses: actions/checkout@v3
         with:
diff --git a/.github/workflows/ios.yml b/.github/workflows/ios.yml
index 942fdf609..7dabccfe1 100644
--- a/.github/workflows/ios.yml
+++ b/.github/workflows/ios.yml
@@ -41,7 +41,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ 'macos-13' ]
+        os: [ 'macos-14' ]
         xcode_version: ${{ fromJson(needs.prepare_matrix.outputs.matrix_xcode_version) }}
     steps:
       - uses: lukka/get-cmake@latest
@@ -66,7 +66,7 @@ jobs:
         uses: actions/setup-python@v4
         with:
           python-version: 3.8
-          architecture: "x64"
+          architecture: "arm64"
 
       - name: Install prerequisites
         run: |
diff --git a/.github/workflows/update-dependencies.yml b/.github/workflows/update-dependencies.yml
index 042a9f63a..23db829d3 100644
--- a/.github/workflows/update-dependencies.yml
+++ b/.github/workflows/update-dependencies.yml
@@ -30,7 +30,7 @@ env:
 jobs:
   update_dependencies:
     name: update-deps
-    runs-on: macos-13
+    runs-on: macos-14
     steps:
       - name: Get token for firebase-workflow-trigger
         uses: tibdex/github-app-token@v1
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9b683ebc9..aea6d80a3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -157,6 +157,11 @@ if(APPLE)
   # build output for our Objective-C++ files much too verbose.
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-nullability-completeness")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-nullability-completeness")
+  if(DESKTOP)
+    # Mac desktop Firestore build requires -Wno-deprecated-declarations
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-deprecated-declarations")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-deprecated-declarations")
+  endif()
 endif()
 
 if(DESKTOP AND NOT MSVC AND NOT APPLE)
diff --git a/release_build_files/readme.md b/release_build_files/readme.md
index 48e1b565b..4a07c05d5 100644
--- a/release_build_files/readme.md
+++ b/release_build_files/readme.md
@@ -451,7 +451,7 @@ Firebase Cloud Messaging (stub) | firebase_messaging.framework
 User Messaging Platform (stub)  | libfirebase_ump.a
 |                               | libfirebase_app.a
 
-The provided libraries have been tested using Xcode 14.1. When building C++
+The provided libraries have been tested using Xcode 16.2. When building C++
 desktop apps on OS X, you will need to link the `gssapi_krb5` and `pthread`
 system libraries, as well as the `CoreFoundation`, `Foundation`, `GSS`, and
 `Security` OS X system frameworks (consult your compiler documentation for more
@@ -656,6 +656,8 @@ code.
 ## Release Notes
 ### 12.8.0
 -   Changes
+    - General (iOS, tvOS, Desktop): iOS, tvOS, and macOS SDKs are now built
+      using Xcode 16.2.
     - UMP: Moved the User Messaging Platform SDK to its own top-level
       library and to the firebase::ump namespace. The version in the
       GMA library (in firebase::gma::ump) has been deprecated and will
diff --git a/scripts/gha/print_matrix_configuration.py b/scripts/gha/print_matrix_configuration.py
index 4d07dbfd4..3dd900d1c 100644
--- a/scripts/gha/print_matrix_configuration.py
+++ b/scripts/gha/print_matrix_configuration.py
@@ -73,35 +73,35 @@
 PARAMETERS = {
   "desktop": {
     "matrix": {
-      "os": ["ubuntu-22.04", "macos-13"],
+      "os": ["ubuntu-22.04", "macos-14"],
       "build_type": ["Release", "Debug"],
-      "architecture": ["x64", "x86"],
+      "architecture": ["x64", "x86", "arm64"],
       "msvc_runtime": ["static","dynamic"],
-      "xcode_version": ["15.1"],
-      "python_version": ["3.7"],
+      "xcode_version": ["16.2"],
+      "python_version": ["3.8"],
 
       EXPANDED_KEY: {
-        "os": ["ubuntu-22.04", "macos-13", "windows-latest"],
-        "xcode_version": ["15.1"],
+        "os": ["ubuntu-22.04", "macos-14", "windows-latest"],
+        "xcode_version": ["16.2"],
       }
     }
   },
 
   "android": {
     "matrix": {
-      "os": ["ubuntu-22.04", "macos-13", "windows-latest"],
-      "architecture": ["x64"],
-      "python_version": ["3.7"],
+      "os": ["ubuntu-22.04", "macos-14", "windows-latest"],
+      "architecture": ["x64", "arm64"],
+      "python_version": ["3.8"],
 
       EXPANDED_KEY: {
-        "os": ["ubuntu-22.04", "macos-13", "windows-latest"]
+        "os": ["ubuntu-22.04", "macos-14", "windows-latest"]
       }
     }
   },
 
   "integration_tests": {
     "matrix": {
-      "os": ["ubuntu-22.04", "macos-13", "windows-latest"],
+      "os": ["ubuntu-22.04", "macos-14", "windows-latest"],
       "platform": ["Desktop", "Android", "iOS", "tvOS"],
       "ssl_lib": ["openssl"],
       "android_device": ["android_target", "emulator_ftl_target"],
@@ -113,7 +113,7 @@
       "msvc_runtime": ["dynamic"],
       "cpp_compiler_windows": ["VisualStudio2019"],
       "cpp_compiler_linux": ["clang-11.0"],
-      "xcode_version": ["15.1"],  # only the first one is used
+      "xcode_version": ["16.2"],  # only the first one is used
       "ndk_version": ["r22b"],
       "platform_version": ["28"],
       "build_tools_version": ["28.0.3"],
@@ -141,10 +141,10 @@
 
   "ios": {
     "matrix": {
-      "xcode_version": ["15.1"],
+      "xcode_version": ["16.2"],
 
       EXPANDED_KEY: {
-        "xcode_version": ["15.1"]
+        "xcode_version": ["16.2"]
       }
     }
   },