diff --git a/src/airflow/dags/dag_preprocess.py b/src/airflow/dags/dag_preprocess.py
new file mode 100644
index 000000000..742365032
--- /dev/null
+++ b/src/airflow/dags/dag_preprocess.py
@@ -0,0 +1,42 @@
+"""Apache Airflow workflow to run the Preprocess part of the pipeline."""
+
+from __future__ import annotations
+
+from functools import partial
+
+from airflow.models.dag import DAG
+from common_airflow import (
+    create_cluster,
+    delete_cluster,
+    outputs,
+    shared_dag_kwargs,
+    submit_pyspark_job,
+)
+
+# Workflow specific configuration.
+CLUSTER_NAME = "otg-preprocess"
+SPARK_WRITE_MODE = "append"
+submit_pyspark_job_partial = partial(submit_pyspark_job, CLUSTER_NAME)
+
+
+with DAG(
+    dag_id="otg-preprocess",
+    description="Open Targets Genetics — Preprocess Workflow",
+    **shared_dag_kwargs,
+):
+    # Ingest FinnGen.
+    ingest_finngen = submit_pyspark_job_partial(
+        task_id="ingest-finngen",
+        python_module_path="finngen.py",
+        args=dict(
+            finngen_phenotype_table_url="https://r9.finngen.fi/api/phenos",
+            finngen_release_prefix="FINNGEN_R9",
+            finngen_summary_stats_url_prefix="gs://finngen-public-data-r9/summary_stats/finngen_R9_",
+            finngen_summary_stats_url_suffix=".gz",
+            finngen_study_index_out=f"{outputs}/preprocess/finngen/study_index",
+            spark_write_mode=SPARK_WRITE_MODE,
+        ),
+    )
+
+    # Assemble the ingestion actions into DAG.
+    (create_cluster(CLUSTER_NAME) >> [ingest_finngen] >> delete_cluster(CLUSTER_NAME))