Orso Ipato (Latin Ursus) is the third traditional Doge of Venice (726–742) and the first historically known.

Sometime in the early 8th century, he is elected to lead the Venetians and granted the title of dux, which has morphed in the Venetian dialect into doge.

He is not a duke.

Orso himself comes from Heraclea.

He is eventually recognized by the Byzantine Emperor Leo III the Isaurian, who gives him the title hypatos.

His descendants surname themselves Ipato on the basis of this imperial honorific.