The vastus lateralis (also vastus lateralis muscle, vastus externus, latin: musculus vastus lateralis) is the largest of the quadriceps femoris muscles, located in the lateral part of the anterior compartment of the thigh.
The vastus lateralis originates from the upper half of the lateral (external) lip of the linea aspera on the posterior surface of the femur.
The vastus lateralis passes over the knee and inserts along with the other muscles of the quadriceps femoris onto the tibial tuberosity.
The main function of the vastus lateralis is extension of the knee.
The vastus lateralis is innervated by the femoral nerve.