The great (also called greater) saphenous vein is the large subcutaneous vein of the leg and thigh.

It runs up the medial side of the leg and the thigh, from the foot. It enters into the femoral vein at the femoral triangle through an opening in the surrounding fascia.

This vein is often removed by cardiothoracic surgeons to be used for auto-transplantation in coronary artery bypass operationsss.