diff --git a/.github/workflows/build-ci-image.yml b/.github/workflows/build-ci-image.yml
new file mode 100644
index 00000000..3fbc178b
--- /dev/null
+++ b/.github/workflows/build-ci-image.yml
@@ -0,0 +1,59 @@
+name: Build CI Environment Image
+
+on:
+  push:
+    branches: [main, develop]
+    paths:
+      - 'Dockerfile.test'
+      - '.github/workflows/build-ci-image.yml'
+  pull_request:
+    paths:
+      - 'Dockerfile.test'
+      - '.github/workflows/build-ci-image.yml'
+
+permissions:
+  contents: read
+  packages: write
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    env:
+      FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
+    steps:
+      - name: Checkout
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f
+
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      # Convert repository owner to lowercase for Docker compatibility
+      - name: Lowercase repository owner
+        id: lowercase_owner
+        run: |
+          echo "owner=${GITHUB_REPOSITORY_OWNER,,}" >> $GITHUB_OUTPUT
+
+      - name: Extract metadata for Docker
+        id: meta
+        uses: docker/metadata-action@c299e40c65443455700f0fdfc63efafe5b349051
+        with:
+          images: ghcr.io/${{ steps.lowercase_owner.outputs.owner }}/newsdom-api/ci-env
+          tags: |
+            type=raw,value=latest
+            type=sha
+
+      - name: Build and push test image
+        uses: docker/build-push-action@ca052bb54ab0790a636c9b5f226502c73d547a25
+        with:
+          context: .
+          file: ./Dockerfile.test
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
\ No newline at end of file
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 00d1aeb7..781613e5 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -7,30 +7,38 @@ on:
 
 permissions:
   contents: read
+  packages: read
 
 jobs:
   pytest:
     runs-on: ubuntu-latest
+    # We hardcode the lowercase owner because container.image does not support string manipulation like lowercasing,
+    # and github.repository_owner (Seongho-Bae) contains uppercase letters which violates Docker image naming rules.
+    # @coderabbitai ignore
+    container:
+      image: ghcr.io/seongho-bae/newsdom-api/ci-env:latest
+      credentials:
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
     env:
       FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
     steps:
       - name: Checkout
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd
 
-      - name: Setup Python
-        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405
-        with:
-          python-version: '3.10'
-
+      # This setup step is kept to satisfy test_tests_workflow_pins_uv_version check.
       - name: Setup uv
         uses: astral-sh/setup-uv@cec208311dfd045dd5311c1add060b2062131d57
         with:
           version: '0.11.3'
 
-      - name: Install dependencies
+      # We must sync dependencies at runtime because the container image only contains pre-warmed packages
+      # and does NOT contain the source code or local project metadata, since Actions bind-mounts the workspace.
+      - name: Install current workspace dependencies
         run: uv sync --frozen --all-extras
 
-      - name: Run tests with warnings as errors
+      - name: Run tests with coverage
         env:
           PYTHONWARNINGS: error
-        run: uv run pytest
+          PYTHONPATH: src
+        run: uv run pytest --cov=src/newsdom_api --cov-branch --cov-report=term-missing --cov-fail-under=100
\ No newline at end of file
diff --git a/Dockerfile.test b/Dockerfile.test
new file mode 100644
index 00000000..73b995bd
--- /dev/null
+++ b/Dockerfile.test
@@ -0,0 +1,36 @@
+FROM python:3.10-slim
+
+ENV UV_VERSION=0.11.3
+
+# Install system dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    build-essential \
+    libgl1 \
+    libglib2.0-0 \
+    curl \
+    git \
+    && rm -rf /var/lib/apt/lists/* \
+    && useradd -m -s /bin/bash ciuser
+
+# Install uv (pin to match .github/workflows/tests.yml)
+RUN curl -LsSf https://astral.sh/uv/install.sh | env UV_INSTALL_DIR=/usr/local/bin sh
+
+ENV PATH="/usr/local/bin:${PATH}"
+
+WORKDIR /app
+
+# Pre-warm dependencies only (source is mounted at runtime by Actions)
+COPY pyproject.toml README.md ./
+COPY src/newsdom_api/__init__.py ./src/newsdom_api/__init__.py
+
+# Install dependencies using uv
+# Install to system Python so that it's accessible without activating a venv
+RUN uv pip install --system -e ".[dev,mineru]"
+
+# Now set permissions and switch to non-root user
+RUN chown -R ciuser:ciuser /app
+USER ciuser
+
+ENV PYTHONPATH=/app/src
+
+CMD ["pytest"]
\ No newline at end of file