The medial circumflex femoral vein is a blood vessel located in the leg. It is an extension of the major femoral vein and runs up the thigh. Unlike the accompanying femoral artery, the femoral vein and its branches direct blood flow towards the heart.

The medial circumflex femoral vein is one of the components of a region in the thigh known as the femoral triangle. The vein is located between the parts of the thigh known as the inguinal ligament, the sartorius muscle, and the abductor longus muscle. It travels within close boundary of the femoral nerve, femoral artery, and the deep inguinal lymph nodes. In conjunction with the femoral triangle, the medial circumflex extension plays an important part in maintaining healthy blood flow in the leg and groin.