The gluteus maximus (also gluteus maximus muscle, latin: musculus gluteus maximus) is the largest and most superficial of the three gluteal muscles and forms the surface anatomy of the gluteal region or buttocks.
The gluteus maximus arises from the outer surface of the ileum behind the posterior gluteal line, from the posterior surface of the sacrum and coccyx, as well as from the sacrotuberous ligament and the thoracolumbar fascia.
The gluteus maximus inserts into the iliotibial band of the fascia lata and into the gluteal tuberosity between the adductor magnus and vastus lateralis muscles.
The main functions of the gluteus maximus are to extend and externally rotate the hip. The gluteus maximus also supports the hip joint.
The gluteus maximus is innervated by the inferior gluteal nerve that arises from the sacral plexus.