diff --git a/.github/workflows/core-llm-test.yml b/.github/workflows/core-llm-test.yml
index da6dd5b096..7c690ae4a8 100644
--- a/.github/workflows/core-llm-test.yml
+++ b/.github/workflows/core-llm-test.yml
@@ -20,7 +20,7 @@ jobs:
   test:
     strategy:
       matrix:
-        llm: ["openai", "gemini", "anthropic"]
+        llm: ["openai", "gemini", "anthropic", "deepseek"]
         python-version: ["3.9"]
         os: [ubuntu-latest]
       fail-fast: false
@@ -46,13 +46,13 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install packages and dependencies
-        if: matrix.llm == 'openai'
+        if: matrix.llm == 'openai' || matrix.llm == 'deepseek'
         run: |
           docker --version
           uv pip install --system -e ".[test,redis,interop]"
           python -c "import autogen"
       - name: Install packages for ${{ matrix.llm }}
-        if: matrix.llm != 'openai'
+        if: matrix.llm != 'openai' && matrix.llm != 'deepseek'
         run: |
           docker --version
           uv pip install --system -e ".[test,redis,interop,${{ matrix.llm }}]"
@@ -62,6 +62,7 @@ jobs:
           OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
           GEMINI_API_KEY: ${{ secrets.GEMINI_API_KEY }}
           ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
+          DEEPSEEK_API_KEY: ${{ secrets.DEEPSEEK_API_KEY }}
           AZURE_OPENAI_API_KEY: ${{ secrets.AZURE_OPENAI_API_KEY }}
           AZURE_OPENAI_API_BASE: ${{ secrets.AZURE_OPENAI_API_BASE }}
           OAI_CONFIG_LIST: ${{ secrets.OAI_CONFIG_LIST }}
diff --git a/pyproject.toml b/pyproject.toml
index 3684cafa09..53dea14152 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -256,6 +256,7 @@ markers = [
     "openai",
     "gemini",
     "anthropic",
+    "deepseek",
     "redis",
     "docker",
 ]
diff --git a/scripts/test-core-llm.sh b/scripts/test-core-llm.sh
index 9d4e9f7af1..3b4f551109 100755
--- a/scripts/test-core-llm.sh
+++ b/scripts/test-core-llm.sh
@@ -5,7 +5,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 # Default mark if none is provided
-DEFAULT_MARK="openai or gemini or anthropic"
+DEFAULT_MARK="openai or gemini or anthropic or deepseek"
 
 # Initialize MARK as the default value
 MARK="$DEFAULT_MARK"
diff --git a/scripts/test-skip-llm.sh b/scripts/test-skip-llm.sh
index acbe5bf410..0747154abb 100755
--- a/scripts/test-skip-llm.sh
+++ b/scripts/test-skip-llm.sh
@@ -4,7 +4,7 @@
 #
 # SPDX-License-Identifier: Apache-2.0
 
-base_filter="not (openai or gemini or anthropic)"
+base_filter="not (openai or gemini or anthropic or deepseek)"
 args=()
 while [[ $# -gt 0 ]]; do
 	if [[ "$1" == "-m" ]]; then
diff --git a/test/conftest.py b/test/conftest.py
index 52bf8e7191..2b946d2605 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -295,6 +295,16 @@ def credentials_anthropic_claude_sonnet() -> Credentials:
     )
 
 
+@pytest.fixture
+def credentials_deepseek_reasoner() -> Credentials:
+    return get_llm_credentials(
+        "DEEPSEEK_API_KEY",
+        model="deepseek-reasoner",
+        api_type="deepseek",
+        filter_dict={"tags": ["deepseek-reasoner"]},
+    )
+
+
 def get_mock_credentials(model: str, temperature: float = 0.6) -> Credentials:
     llm_config = {
         "config_list": [
diff --git a/test/test_conftest.py b/test/test_conftest.py
index 28da381d12..0700d33da2 100644
--- a/test/test_conftest.py
+++ b/test/test_conftest.py
@@ -32,3 +32,9 @@ def test_credentials_from_test_param_fixture(
         assert first_config["api_type"] == "anthropic"
     else:
         assert False, f"Unknown LLM fixture: {current_llm}"
+
+
+@pytest.mark.deepseek
+def test_credentials_deepseek_reasoner_api_key_is_set(credentials_deepseek_reasoner: Credentials) -> None:
+    assert len(credentials_deepseek_reasoner.config_list) > 0
+    assert credentials_deepseek_reasoner.config_list[0]["api_key"] is not None