Zygomaticus major is one of the muscles of facial expression. It acts to raise and evert the margin of the upper lip, as required during smiling.
On each side, its origin is superior and medial to that of zygomaticus major on the zygomatic bone. It passes anteriorly, inferiorly and medially to insert into the skin and muscle of the upper lip. During its course, the facial artery and vein lie deep to it.
Its blood supply is the facial artery.
The innervation of zygomaticus major is from the buccal branch of the facial nerve (VII).