diff --git a/.github/workflows/.tests.yaml b/.github/workflows/.tests.yaml
new file mode 100644
index 00000000000..fa7859e585d
--- /dev/null
+++ b/.github/workflows/.tests.yaml
@@ -0,0 +1,111 @@
+# Reusable workflow consumed by tests.yaml; used to share a single matrix across jobs.
+name: .tests
+
+on:
+  workflow_call:
+    inputs:
+      os-name:
+        required: true
+        type: string
+      os-image:
+        required: true
+        type: string
+      python-version:
+        required: true
+        type: string
+      run-mypy:
+        required: true
+        type: boolean
+      run-pytest:
+        required: true
+        type: boolean
+      run-pytest-export:
+        required: true
+        type: boolean
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  mypy:
+    name: mypy
+    runs-on: ${{ inputs.os-image }}
+    if: inputs.run-mypy
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: ./.github/actions/bootstrap-poetry
+        with:
+          python-version: ${{ inputs.python-version }}
+
+      - run: poetry install --sync
+
+      - run: poetry env info
+
+      - run: poetry show
+
+      - uses: actions/cache@v4
+        with:
+          path: .mypy_cache
+          key: mypy-${{ inputs.os-image }}-${{ env.pythonLocation }}-${{ hashFiles('pyproject.toml', 'poetry.lock') }}
+          restore-keys: |
+            mypy-${{ inputs.os-image }}-${{ env.pythonLocation }}-
+            mypy-${{ inputs.os-image }}-
+
+      - run: poetry run mypy
+
+  pytest:
+    name: pytest
+    runs-on: ${{ inputs.os-image }}
+    if: inputs.run-pytest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: ./.github/actions/bootstrap-poetry
+        with:
+          python-version: ${{ inputs.python-version }}
+
+      - run: poetry install --sync --with github-actions
+
+      - run: poetry env info
+
+      - run: poetry show
+
+      - run: poetry run pytest --integration -v
+        env:
+          POETRY_TEST_INTEGRATION_GIT_USERNAME: ${{ github.actor }}
+          POETRY_TEST_INTEGRATION_GIT_PASSWORD: ${{ github.token }}
+
+      - run: git diff --exit-code --stat HEAD
+
+  pytest-export:
+    name: pytest (poetry-plugin-export)
+    runs-on: ${{ inputs.os-image }}
+    if: inputs.run-pytest-export
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: ./.github/actions/bootstrap-poetry
+        with:
+          python-version: ${{ inputs.python-version }}
+
+      - run: poetry install --sync --with github-actions
+
+      - run: poetry env info
+
+      - run: poetry show
+
+      - id: poetry-plugin-export
+        run: echo version=$(poetry run pip list --format json | jq -r '.[] | select(.name == "poetry-plugin-export").version') >> $GITHUB_OUTPUT
+
+      - uses: actions/checkout@v4
+        with:
+          path: poetry-plugin-export
+          repository: python-poetry/poetry-plugin-export
+          ref: refs/tags/${{ steps.poetry-plugin-export.outputs.version }}
+
+      - run: poetry run -C .. pytest -v
+        working-directory: ./poetry-plugin-export
+
+      - run: git -C poetry-plugin-export diff --exit-code --stat HEAD
diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 61970b546e9..8e002af7e1d 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -31,6 +31,7 @@ jobs:
           filters: |
             workflow: &workflow
               - '.github/workflows/tests.yaml'
+              - '.github/workflows/.tests.yaml'
             project: &project
               - *workflow
               - 'poetry.lock'
@@ -77,54 +78,11 @@ jobs:
 
       - run: git diff --exit-code --stat HEAD tests/repositories/fixtures/pypi.org
 
-  mypy:
-    name: mypy [${{ matrix.os.name }} / Python ${{ matrix.python-version }}]
-    runs-on: ${{ matrix.os.image }}
-    if: needs.changes.outputs.mypy == 'true'
+  tests-matrix:
+    name: ${{ matrix.os.name }} (Python ${{ matrix.python-version }})
     needs:
-      - changes
       - lockfile
-    strategy:
-      matrix:
-        os:
-          - name: Ubuntu
-            image: ubuntu-22.04
-          - name: macOS
-            image: macos-12
-          - name: Windows
-            image: windows-2022
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
-      fail-fast: false
-    steps:
-      - uses: actions/checkout@v4
-
-      - uses: ./.github/actions/bootstrap-poetry
-        with:
-          python-version: ${{ matrix.python-version }}
-
-      - run: poetry install --sync
-
-      - run: poetry env info
-
-      - run: poetry show
-
-      - uses: actions/cache@v4
-        with:
-          path: .mypy_cache
-          key: mypy-${{ matrix.os.image }}-${{ env.pythonLocation }}-${{ hashFiles('pyproject.toml', 'poetry.lock') }}
-          restore-keys: |
-            mypy-${{ inputs.os-image }}-${{ env.pythonLocation }}-
-            mypy-${{ inputs.os-image }}-
-
-      - run: poetry run mypy
-
-  pytest:
-    name: pytest [${{ matrix.os.name }} / Python ${{ matrix.python-version }}]
-    runs-on: ${{ matrix.os.image }}
-    if: needs.changes.outputs.pytest == 'true'
-    needs:
       - changes
-      - lockfile
     strategy:
       matrix:
         os:
@@ -136,70 +94,16 @@ jobs:
             image: windows-2022
         python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
       fail-fast: false
-    steps:
-      - uses: actions/checkout@v4
-
-      - uses: ./.github/actions/bootstrap-poetry
-        with:
-          python-version: ${{ matrix.python-version }}
-
-      - run: poetry install --sync --with github-actions
-
-      - run: poetry env info
-
-      - run: poetry show
-
-      - run: poetry run pytest --integration -v
-        env:
-          POETRY_TEST_INTEGRATION_GIT_USERNAME: ${{ github.actor }}
-          POETRY_TEST_INTEGRATION_GIT_PASSWORD: ${{ github.token }}
-
-      - run: git diff --exit-code --stat HEAD
-
-  pytest-export:
-    name: pytest (poetry-plugin-export) [${{ matrix.os.name }} / Python ${{ matrix.python-version }}]
-    runs-on: ${{ matrix.os.image }}
-    if: needs.changes.outputs.pytest-export == 'true'
-    needs:
-      - changes
-      - lockfile
-    strategy:
-      matrix:
-        os:
-          - name: Ubuntu
-            image: ubuntu-22.04
-          - name: macOS
-            image: macos-12
-          - name: Windows
-            image: windows-2022
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
-      fail-fast: false
-    steps:
-      - uses: actions/checkout@v4
-
-      - uses: ./.github/actions/bootstrap-poetry
-        with:
-          python-version: ${{ matrix.python-version }}
-
-      - run: poetry install --sync --with github-actions
-
-      - run: poetry env info
-
-      - run: poetry show
-
-      - id: poetry-plugin-export
-        run: echo version=$(poetry run pip list --format json | jq -r '.[] | select(.name == "poetry-plugin-export").version') >> $GITHUB_OUTPUT
-
-      - uses: actions/checkout@v4
-        with:
-          path: poetry-plugin-export
-          repository: python-poetry/poetry-plugin-export
-          ref: refs/tags/${{ steps.poetry-plugin-export.outputs.version }}
-
-      - run: poetry run -C .. pytest -v
-        working-directory: ./poetry-plugin-export
-
-      - run: git -C poetry-plugin-export diff --exit-code --stat HEAD
+    # Use this matrix with multiple jobs defined in a reusable workflow:
+    uses: ./.github/workflows/.tests.yaml
+    with:
+      os-name: ${{ matrix.os.name }}
+      os-image: ${{ matrix.os.image }}
+      python-version: ${{ matrix.python-version }}
+      run-mypy: ${{ needs.changes.outputs.mypy == 'true' }}
+      run-pytest: ${{ needs.changes.outputs.pytest == 'true' }}
+      run-pytest-export: ${{ needs.changes.outputs.pytest-export == 'true' }}
+    secrets: inherit
 
   status:
     name: Status
@@ -208,8 +112,6 @@ jobs:
     needs:
       - lockfile
       - fixtures-pypi
-      - mypy
-      - pytest
-      - pytest-export
+      - tests-matrix
     steps:
       - run: ${{ (contains(needs.*.result, 'failure') || contains(needs.*.result, 'cancelled')) && 'false' || 'true' }}