diff --git a/airflow-core/src/airflow/api/common/trigger_dag.py b/airflow-core/src/airflow/api/common/trigger_dag.py
index 614140b58c4a9..77912f58d2637 100644
--- a/airflow-core/src/airflow/api/common/trigger_dag.py
+++ b/airflow-core/src/airflow/api/common/trigger_dag.py
@@ -50,6 +50,7 @@ def _trigger_dag(
     conf: dict | str | None = None,
     logical_date: datetime | None = None,
     replace_microseconds: bool = True,
+    partition_key: str | None = None,
     session: Session = NEW_SESSION,
 ) -> DagRun | None:
     """
@@ -118,6 +119,7 @@ def _trigger_dag(
         triggered_by=triggered_by,
         triggering_user_name=triggering_user_name,
         state=DagRunState.QUEUED,
+        partition_key=partition_key,
         session=session,
     )
 
@@ -135,6 +137,7 @@ def trigger_dag(
     conf: dict | str | None = None,
     logical_date: datetime | None = None,
     replace_microseconds: bool = True,
+    partition_key: str | None = None,
     session: Session = NEW_SESSION,
 ) -> DagRun | None:
     """
@@ -166,6 +169,7 @@ def trigger_dag(
         replace_microseconds=replace_microseconds,
         triggered_by=triggered_by,
         triggering_user_name=triggering_user_name,
+        partition_key=partition_key,
         session=session,
     )
 
diff --git a/airflow-core/src/airflow/api_fastapi/execution_api/datamodels/dagrun.py b/airflow-core/src/airflow/api_fastapi/execution_api/datamodels/dagrun.py
index 1f73156cebf5a..32b0b7fead07b 100644
--- a/airflow-core/src/airflow/api_fastapi/execution_api/datamodels/dagrun.py
+++ b/airflow-core/src/airflow/api_fastapi/execution_api/datamodels/dagrun.py
@@ -30,6 +30,7 @@ class TriggerDAGRunPayload(StrictBaseModel):
     logical_date: UtcDateTime | None = None
     conf: dict = Field(default_factory=dict)
     reset_dag_run: bool = False
+    partition_key: str | None = None
 
 
 class DagRunStateResponse(BaseModel):
diff --git a/airflow-core/src/airflow/api_fastapi/execution_api/routes/dag_runs.py b/airflow-core/src/airflow/api_fastapi/execution_api/routes/dag_runs.py
index 7763850b5ee4e..189201db68812 100644
--- a/airflow-core/src/airflow/api_fastapi/execution_api/routes/dag_runs.py
+++ b/airflow-core/src/airflow/api_fastapi/execution_api/routes/dag_runs.py
@@ -122,6 +122,7 @@ def trigger_dag_run(
             logical_date=payload.logical_date,
             triggered_by=DagRunTriggeredByType.OPERATOR,
             replace_microseconds=False,
+            partition_key=payload.partition_key,
             session=session,
         )
     except DagRunAlreadyExists:
diff --git a/airflow-core/src/airflow/api_fastapi/execution_api/versions/v2025_11_07.py b/airflow-core/src/airflow/api_fastapi/execution_api/versions/v2025_11_07.py
index b11811179f1e8..9363d825cef89 100644
--- a/airflow-core/src/airflow/api_fastapi/execution_api/versions/v2025_11_07.py
+++ b/airflow-core/src/airflow/api_fastapi/execution_api/versions/v2025_11_07.py
@@ -20,6 +20,7 @@
 from cadwyn import ResponseInfo, VersionChange, convert_response_to_previous_version_for, schema
 
 from airflow.api_fastapi.execution_api.datamodels.asset_event import AssetEventResponse, AssetEventsResponse
+from airflow.api_fastapi.execution_api.datamodels.dagrun import TriggerDAGRunPayload
 from airflow.api_fastapi.execution_api.datamodels.taskinstance import DagRun, TIRunContext
 
 
@@ -31,6 +32,7 @@ class AddPartitionKeyField(VersionChange):
     instructions_to_migrate_to_previous_version = (
         schema(DagRun).field("partition_key").didnt_exist,
         schema(AssetEventResponse).field("partition_key").didnt_exist,
+        schema(TriggerDAGRunPayload).field("partition_key").didnt_exist,
     )
 
     @convert_response_to_previous_version_for(TIRunContext)  # type: ignore[arg-type]
diff --git a/airflow-core/tests/unit/api_fastapi/execution_api/versions/head/test_dag_runs.py b/airflow-core/tests/unit/api_fastapi/execution_api/versions/head/test_dag_runs.py
index 91c9c314a0e6d..1691ad535310b 100644
--- a/airflow-core/tests/unit/api_fastapi/execution_api/versions/head/test_dag_runs.py
+++ b/airflow-core/tests/unit/api_fastapi/execution_api/versions/head/test_dag_runs.py
@@ -61,6 +61,33 @@ def test_trigger_dag_run(self, client, session, dag_maker):
         assert dag_run.conf == {"key1": "value1"}
         assert dag_run.logical_date == logical_date
 
+    def test_trigger_dag_run_with_partition_key(self, client, session, dag_maker):
+        dag_id = "test_trigger_dag_run_partition_key"
+        run_id = "test_run_id"
+        logical_date = timezone.datetime(2025, 2, 20)
+        partition_key = "2025-02-20"
+
+        with dag_maker(dag_id=dag_id, session=session, serialized=True):
+            EmptyOperator(task_id="test_task")
+
+        session.commit()
+
+        response = client.post(
+            f"/execution/dag-runs/{dag_id}/{run_id}",
+            json={
+                "logical_date": logical_date.isoformat(),
+                "conf": {"key1": "value1"},
+                "partition_key": partition_key,
+            },
+        )
+
+        assert response.status_code == 204
+
+        dag_run = session.scalars(select(DagRun).where(DagRun.run_id == run_id)).one()
+        assert dag_run.conf == {"key1": "value1"}
+        assert dag_run.logical_date == logical_date
+        assert dag_run.partition_key == partition_key
+
     def test_trigger_dag_run_dag_not_found(self, client):
         """Test that a DAG that does not exist cannot be triggered."""
         dag_id = "dag_not_found"
diff --git a/task-sdk/src/airflow/sdk/api/datamodels/_generated.py b/task-sdk/src/airflow/sdk/api/datamodels/_generated.py
index 149aa5d7dcb0d..0621df05b0eed 100644
--- a/task-sdk/src/airflow/sdk/api/datamodels/_generated.py
+++ b/task-sdk/src/airflow/sdk/api/datamodels/_generated.py
@@ -355,6 +355,7 @@ class TriggerDAGRunPayload(BaseModel):
     logical_date: Annotated[AwareDatetime | None, Field(title="Logical Date")] = None
     conf: Annotated[dict[str, Any] | None, Field(title="Conf")] = None
     reset_dag_run: Annotated[bool | None, Field(title="Reset Dag Run")] = False
+    partition_key: Annotated[str | None, Field(title="Partition Key")] = None
 
 
 class UpdateHITLDetailPayload(BaseModel):