What is the largest muscle in the human body?

The largest muscle in the human body is the gluteus maximus.

Located in the buttocks, it is the largest and most superficial of the three gluteal muscles; the others are the gluteus medius and gluteus minimus. Its main action is hip extension, meaning it helps move the thigh backward and straighten the hip. It also contributes to external rotation and helps stabilize the trunk and knee during movement.

Its size is closely associated with human bipedalism. A powerful gluteus maximus helps maintain an upright posture and is especially important during running, climbing, jumping, and rising from a seated position. Research suggests the muscle’s enlargement in humans was particularly linked to running and control of the trunk.

A common mix-up is confusing the largest muscle with the “strongest” muscle, a label that depends on how strength is measured. The quadriceps are a large muscle group at the front of the thigh, while the hamstrings are a group at the back; neither is a single muscle and neither is the standard answer to this question.