The lumbar plexus (latin: plexus lumbalis) is a network of nerves in the lumbar region of the human body.
The lumbar plexus is formed by the ventral branches of the twelfth thoracic, and the first, second, third and fourth lumbar spinal nerves (T12, L1 - L4).
The lumbar plexus is situated within the psoas major.
Short motor branches arise from the lumbar plexus, that supply the psoas major, psoas minor and quadratus lumborum muscles.
From the lumbar plexus also arise six long branches: the femoral nerve, the lateral femoral cutaneous nerve, the genitofemoral nerve, the obturator nerve, the iliohypogastric nerve and the ilioinguinal nerve.