Levator labii superioris alaeque nasi is one of the muscles of facial expression acting on the mouth and nose. It must not be confused with levator labii superioris, a muscle that lies more laterally.
Levator labii superioris alaeque nasi arises from the superior frontal process of the maxilla. It passes vertically downwards to insert into the skin of the lateral side of the nostril and the upper lip.
It acts to dilate the nostril and raise the upper lip.
It is innervated by the buccal branch of the facial nerve (CN VII).