Ao was an Assyrian deity called "The Intelligent Guide," "The Lord of the Visible World," "The Lord of Knowledge, Glory, and Life." His most usual symbol was a serpent. In concert with the other great divinities, the city of Dursharyakin (Khorsabad) was dedicated to Ao by Sargon II.
Ao was also, according to Wilkinson, the name of an uncertain Egyptian deity, sometimes called Moui. He was represented as a kingly figure, with an upright feather on his head.