diff --git a/.github/workflows/build_all.yml b/.github/workflows/build_all.yml
index 376ef74b1f..49e6f58fd6 100644
--- a/.github/workflows/build_all.yml
+++ b/.github/workflows/build_all.yml
@@ -122,54 +122,73 @@ jobs:
       arch: universal
       macos-combine-only: true
     secrets: inherit
-  unit_tests:
-    name: Unit Tests
-    # Tests are built on the aarch64 leg by default (faster GitHub arm runner),
-    # so run them there; self-hosted builds them on the amd64 server instead.
-    runs-on: ${{ vars.SELF_HOSTED && 'orca-lnx-server' || 'ubuntu-24.04-arm' }}
+  # One test job per built arch, on the runner that built it.
+  unit_tests_linux_x86_64:
+    name: Linux x86_64
     needs: build_linux
     if: ${{ !cancelled() && success() }}
+    uses: ./.github/workflows/unit_tests.yml
+    with:
+      os: ${{ vars.SELF_HOSTED && 'orca-lnx-server' || 'ubuntu-24.04' }}
+      artifact: ${{ github.sha }}-tests-linux-x86_64
+  unit_tests_linux_aarch64:
+    name: Linux aarch64
+    needs: build_linux
+    if: ${{ !cancelled() && success() }}
+    uses: ./.github/workflows/unit_tests.yml
+    with:
+      os: ubuntu-24.04-arm
+      artifact: ${{ github.sha }}-tests-linux-aarch64
+  unit_tests_windows_x64:
+    name: Windows x64
+    needs: build_windows
+    if: ${{ !cancelled() && success() }}
+    uses: ./.github/workflows/unit_tests.yml
+    with:
+      os: ${{ vars.SELF_HOSTED && 'orca-win-server' || 'windows-latest' }}
+      artifact: ${{ github.sha }}-tests-windows-x64
+  unit_tests_windows_arm64:
+    name: Windows arm64
+    needs: build_windows
+    if: ${{ !cancelled() && success() }}
+    uses: ./.github/workflows/unit_tests.yml
+    with:
+      os: windows-11-arm
+      artifact: ${{ github.sha }}-tests-windows-arm64
+      test-dir: build-arm64/tests
+  unit_tests_macos_arm64:
+    name: macOS arm64
+    needs: build_macos_arch
+    if: ${{ !cancelled() && success() }}
+    uses: ./.github/workflows/unit_tests.yml
+    with:
+      os: ${{ vars.SELF_HOSTED && 'orca-macos-arm64' || 'macos-14' }}
+      artifact: ${{ github.sha }}-tests-macos-arm64
+      test-dir: build/arm64/tests
+  publish_test_results:
+    name: Publish Test Results
+    needs: [unit_tests_linux_x86_64, unit_tests_linux_aarch64, unit_tests_windows_x64, unit_tests_windows_arm64, unit_tests_macos_arm64]
+    if: ${{ !cancelled() }}
+    runs-on: ubuntu-latest
     steps:
-      - name: Checkout
-        uses: actions/checkout@v7
-        with:
-          sparse-checkout: |
-            .github
-            scripts
-            tests
-      - name: Apt-Install Dependencies
-        if: ${{ !vars.SELF_HOSTED }}
-        uses: ./.github/actions/apt-install-deps
-      - name: Restore Test Artifact
+      - name: Download Test Results
         uses: actions/download-artifact@v8
         with:
-          name: ${{ github.sha }}-tests
-      - uses: lukka/get-cmake@latest
-        with:
-          cmakeVersion: "~4.3.0"  # use most recent 4.3.x version
-          useLocalCache: true         # <--= Use the local cache (default is 'false').
-          useCloudCache: true
-      - name: Unpackage and Run Unit Tests
-        timeout-minutes: 20
-        run: |
-          tar -xvf build_tests.tar
-          scripts/run_unit_tests.sh
-      - name: Upload Test Logs
-        uses: actions/upload-artifact@v7
-        if: ${{ failure() }}
-        with:
-          name: unit-test-logs
-          path: build/tests/**/*.log
+          pattern: test-results-*
+          path: test-results
+      # Best-effort: a read-only token (e.g. fork PRs) can't write the check, so
+      # don't let a publish failure fail the run. The test jobs gate correctness.
       - name: Publish Test Results
-        if: always()
+        continue-on-error: true
         uses: EnricoMi/publish-unit-test-result-action@v2
         with:
-          files: "ctest_results.xml"
-      - name: Delete Test Artifact
+          files: "test-results/**/*.xml"
+      - name: Delete Test Results
         if: success()
         uses: geekyeggo/delete-artifact@v6
         with:
-          name: ${{ github.sha }}-tests
+          name: test-results-*
+          failOnError: false
   flatpak:
     name: "Flatpak"
     container:
diff --git a/.github/workflows/build_orca.yml b/.github/workflows/build_orca.yml
index ffe4c35f8d..21c65283a9 100644
--- a/.github/workflows/build_orca.yml
+++ b/.github/workflows/build_orca.yml
@@ -141,8 +141,26 @@ jobs:
       - name: Build slicer mac
         if: runner.os == 'macOS' && !inputs.macos-combine-only
         working-directory: ${{ github.workspace }}
+        # arm64 only: build the tests here; the unit_tests_macos job runs them.
+        env:
+          ORCA_TESTS_BUILD_ONLY: ${{ inputs.arch == 'arm64' && '1' || '' }}
         run: |
-          ./build_release_macos.sh -s -n -x ${{ !vars.SELF_HOSTED && '-1' || '' }} -a ${{ inputs.arch }} -t 10.15
+          ./build_release_macos.sh -s -n -x ${{ !vars.SELF_HOSTED && '-1' || '' }} -a ${{ inputs.arch }} -t 10.15 ${{ inputs.arch == 'arm64' && '-T' || '' }}
+
+      - name: Pack unit tests mac
+        if: runner.os == 'macOS' && !inputs.macos-combine-only && inputs.arch == 'arm64'
+        working-directory: ${{ github.workspace }}
+        run: tar -cvf build_tests.tar build/arm64/tests
+
+      - name: Upload Test Artifact mac
+        if: runner.os == 'macOS' && !inputs.macos-combine-only && inputs.arch == 'arm64'
+        uses: actions/upload-artifact@v7
+        with:
+          name: ${{ github.sha }}-tests-macos-arm64
+          overwrite: true
+          path: build_tests.tar
+          retention-days: 5
+          if-no-files-found: error
 
       - name: Pack macOS app bundle ${{ inputs.arch }}
         if: runner.os == 'macOS' && !inputs.macos-combine-only
@@ -335,11 +353,28 @@ jobs:
         # env:
         #   WindowsSdkDir: 'C:\Program Files (x86)\Windows Kits\10\'
         #   WindowsSDKVersion: '10.0.26100.0\'
+        # "tests" builds the unit tests too; the unit_tests_windows_* jobs run them.
         run: |
           $arch = "${{ inputs.arch }}"
-          if ($arch -eq "arm64") { .\build_release_vs.bat slicer arm64 } else { .\build_release_vs.bat slicer }
+          if ($arch -eq "arm64") { .\build_release_vs.bat slicer arm64 tests } else { .\build_release_vs.bat slicer tests }
         shell: pwsh
 
+      - name: Pack unit tests Win
+        if: runner.os == 'Windows'
+        working-directory: ${{ github.workspace }}
+        shell: pwsh
+        run: tar -cvf build_tests.tar ${{ env.BUILD_DIR }}/tests
+
+      - name: Upload Test Artifact Win
+        if: runner.os == 'Windows'
+        uses: actions/upload-artifact@v7
+        with:
+          name: ${{ github.sha }}-tests-windows-${{ inputs.arch }}
+          overwrite: true
+          path: build_tests.tar
+          retention-days: 5
+          if-no-files-found: error
+
       # NSIS is x86-only; it runs (and the installer it emits runs) under ARM64's
       # x86 emulation, packaging the native arm64 payload from build-arm64.
       - name: Create installer Win
@@ -452,26 +487,22 @@ jobs:
         if: runner.os == 'Linux'
         shell: bash
         run: |
-          # Build + tar the unit tests (-t) only on the leg that runs them: the
-          # aarch64 leg by default (faster GitHub arm runner), or amd64 when using
-          # self-hosted runners (no arm self-hosted server). unit_tests downloads
-          # this tarball. The profile validator is built with -s, so amd64 keeps it.
-          tests=${{ (!vars.SELF_HOSTED && inputs.arch == 'aarch64') || (vars.SELF_HOSTED && inputs.arch != 'aarch64') }}
-          if $tests; then flags=-istrlL; else flags=-isrlL; fi
-          ./build_linux.sh "$flags"
+          # Build + tar the unit tests (-t) on both Linux legs so each arch
+          # (x86_64 + aarch64) gets tested by its own unit_tests_linux_* job.
+          ./build_linux.sh -istrlL
           ./scripts/check_appimage_libs.sh ./build/package ./build/package/bin/orca-slicer
           appimage=./build/OrcaSlicer_Linux_AppImage${{ env.ubuntu-ver-str }}${{ env.arch_suffix }}_${{ env.ver }}.AppImage
           mv -n ./build/OrcaSlicer_Linux_V${{ env.ver_pure }}.AppImage "$appimage"
           chmod +x "$appimage"
-          if $tests; then tar -cvpf build_tests.tar build/tests; fi
+          tar -cvf build_tests.tar build/tests
 
         # Use tar because upload-artifacts won't always preserve directory structure
         # and doesn't preserve file permissions
       - name: Upload Test Artifact
-        if: runner.os == 'Linux' && ((!vars.SELF_HOSTED && inputs.arch == 'aarch64') || (vars.SELF_HOSTED && inputs.arch != 'aarch64'))
+        if: runner.os == 'Linux'
         uses: actions/upload-artifact@v7
         with:
-          name: ${{ github.sha }}-tests
+          name: ${{ github.sha }}-tests-linux-${{ inputs.arch == 'aarch64' && 'aarch64' || 'x86_64' }}
           overwrite: true
           path: build_tests.tar
           retention-days: 5
diff --git a/.github/workflows/unit_tests.yml b/.github/workflows/unit_tests.yml
new file mode 100644
index 0000000000..0fe91c7440
--- /dev/null
+++ b/.github/workflows/unit_tests.yml
@@ -0,0 +1,73 @@
+name: Unit Tests
+
+# Download a platform's test artifact, run ctest, and upload the JUnit
+# results for aggregation. Called once per arch from build_all.yml.
+on:
+  workflow_call:
+    inputs:
+      os:
+        required: true
+        type: string
+      artifact:
+        description: Test artifact uploaded by the build leg
+        required: true
+        type: string
+      test-dir:
+        description: Built tests dir; defaults to build/tests, override for arch-separated builds
+        required: false
+        type: string
+        default: build/tests
+
+jobs:
+  unit_tests:
+    # Static "Unit Tests"; the per-arch label is the caller's job name, so the
+    # graph shows e.g. "Windows x64 / Unit Tests".
+    name: Unit Tests
+    runs-on: ${{ inputs.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v7
+        with:
+          # tests/data is referenced by absolute path (TEST_DATA_DIR).
+          sparse-checkout: |
+            .github
+            scripts
+            tests
+      - name: Apt-Install Dependencies
+        if: runner.os == 'Linux' && !vars.SELF_HOSTED
+        uses: ./.github/actions/apt-install-deps
+      - name: Restore Test Artifact
+        uses: actions/download-artifact@v8
+        with:
+          name: ${{ inputs.artifact }}
+      - uses: lukka/get-cmake@latest
+        with:
+          cmakeVersion: "~4.3.0"  # use most recent 4.3.x version
+          useLocalCache: true
+          useCloudCache: true
+      - name: Unpackage and Run Unit Tests
+        timeout-minutes: 20
+        shell: bash
+        run: |
+          tar -xvf build_tests.tar
+          # Multi-config generators (Windows/macOS) need a config; Linux is single-config.
+          scripts/run_unit_tests.sh "${{ inputs.test-dir }}" "${{ runner.os != 'Linux' && 'Release' || '' }}"
+      - name: Upload Test Logs
+        if: ${{ failure() }}
+        uses: actions/upload-artifact@v7
+        with:
+          name: unit-test-logs-${{ inputs.artifact }}
+          path: ${{ inputs.test-dir }}/**/*.log
+      - name: Upload Test Results
+        if: always()
+        uses: actions/upload-artifact@v7
+        with:
+          name: test-results-${{ inputs.artifact }}
+          path: ctest_results.xml
+          retention-days: 5
+          if-no-files-found: warn
+      - name: Delete Test Artifact
+        if: success()
+        uses: geekyeggo/delete-artifact@v6
+        with:
+          name: ${{ inputs.artifact }}
diff --git a/build_release_macos.sh b/build_release_macos.sh
index 8d417695ad..1a86d2c515 100755
--- a/build_release_macos.sh
+++ b/build_release_macos.sh
@@ -59,7 +59,7 @@ while getopts ":dpa:snt:xbc:i:1Tuh" opt; do
         echo "   -c: Set CMake build configuration, default is Release"
         echo "   -i: Add a prefix to ignore during CMake dependency discovery (repeatable), defaults to /opt/local:/usr/local:/opt/homebrew"
         echo "   -1: Use single job for building"
-        echo "   -T: Build and run tests"
+        echo "   -T: Build and run tests (set ORCA_TESTS_BUILD_ONLY=1 to build without running)"
         exit 0
         ;;
     * )
@@ -209,13 +209,10 @@ function build_slicer() {
             cmake --build . --config "$BUILD_CONFIG" --target "$SLICER_BUILD_TARGET"
         )
 
-        if [ "1." == "$BUILD_TESTS". ]; then
-            echo "Running tests for $_ARCH..."
-            (
-                set -x
-                cd "$PROJECT_BUILD_DIR"
-                ctest --build-config "$BUILD_CONFIG" --output-on-failure
-            )
+        # -T also runs the tests; ORCA_TESTS_BUILD_ONLY=1 builds them without
+        # running, so CI can build here and run them in a dedicated job.
+        if [ "1." == "$BUILD_TESTS". ] && [ "1." != "$ORCA_TESTS_BUILD_ONLY". ]; then
+            "$PROJECT_DIR/scripts/run_unit_tests.sh" "build/$_ARCH/tests" "$BUILD_CONFIG"
         fi
 
         echo "Verify localization with gettext..."
diff --git a/build_release_vs.bat b/build_release_vs.bat
index 0c1334d5f7..3288beda4c 100644
--- a/build_release_vs.bat
+++ b/build_release_vs.bat
@@ -20,6 +20,12 @@ for %%a in (%*) do (
     if "%%a"=="-x" set USE_NINJA=1
 )
 
+@REM Check for unit-tests option ("tests")
+set BUILD_TESTS=OFF
+for %%a in (%*) do (
+    if /I "%%a"=="tests" set BUILD_TESTS=ON
+)
+
 if "%USE_NINJA%"=="1" (
     echo Using Ninja Multi-Config generator
     set CMAKE_GENERATOR="Ninja Multi-Config"
@@ -145,10 +151,10 @@ cd %build_dir%
 echo on
 set CMAKE_POLICY_VERSION_MINIMUM=3.5
 if "%USE_NINJA%"=="1" (
-    cmake .. -G %CMAKE_GENERATOR% -DORCA_TOOLS=ON %SIG_FLAG% -DCMAKE_BUILD_TYPE=%build_type%
+    cmake .. -G %CMAKE_GENERATOR% -DORCA_TOOLS=ON %SIG_FLAG% -DBUILD_TESTS=%BUILD_TESTS% -DCMAKE_BUILD_TYPE=%build_type%
     cmake --build . --config %build_type% --target ALL_BUILD
 ) else (
-    cmake .. -G %CMAKE_GENERATOR% -A %arch% -DORCA_TOOLS=ON %SIG_FLAG% -DCMAKE_BUILD_TYPE=%build_type%
+    cmake .. -G %CMAKE_GENERATOR% -A %arch% -DORCA_TOOLS=ON %SIG_FLAG% -DBUILD_TESTS=%BUILD_TESTS% -DCMAKE_BUILD_TYPE=%build_type%
     cmake --build . --config %build_type% --target ALL_BUILD -- -m
 )
 @echo off
diff --git a/scripts/run_unit_tests.sh b/scripts/run_unit_tests.sh
index bd9e969227..f6a01dd3e0 100755
--- a/scripts/run_unit_tests.sh
+++ b/scripts/run_unit_tests.sh
@@ -4,11 +4,21 @@
 # It should only require the directories build/tests, scripts/, and tests/ to function,
 # and cmake (with ctest) installed.
 # (otherwise, update the workflow too, but try to avoid to keep things self-contained)
+#
+# Usage: run_unit_tests.sh [TEST_DIR] [BUILD_CONFIG]
+#   TEST_DIR      directory containing the built tests (default: build/tests)
+#   BUILD_CONFIG  configuration to run; required for multi-config generators
+#                 (Windows/macOS), harmless/omitted for single-config (Linux).
 
 ROOT_DIR="$(dirname "$0")/.."
 
 cd "${ROOT_DIR}" || exit 1
 
+TEST_DIR="${1:-build/tests}"
+BUILD_CONFIG="${2:-}"
+
 # Run the whole suite, excluding tests tagged [NotWorking].
 # --no-tests=error fails the job if the filter matches nothing (instead of passing green).
-ctest --test-dir build/tests -LE "NotWorking" --no-tests=error --output-junit "$(pwd)/ctest_results.xml" --output-on-failure -j
+args=(--test-dir "${TEST_DIR}" -LE "NotWorking" --no-tests=error --output-junit "$(pwd)/ctest_results.xml" --output-on-failure -j)
+[ -n "${BUILD_CONFIG}" ] && args+=(--build-config "${BUILD_CONFIG}")
+ctest "${args[@]}"