Utu in Sumerian mythology was the god of the sun and of justice.

Utu was the son of the moon god Nanna (or Sin Nannar ) and the goddess Ningal, which also had a lunar aspect. His sister was Inanna, which is associated with the planet Venus. With the goddess Aja he begat sons Enmerkar, Gud and Meskiaggasa. In the Epic of Gilgamesh, the hero Gilgamesh, Utu offereth several victims, and asks him to assist him on his journey to the " land of the living ." Utu helps him by paralyzing seven evil demons ( Sebettu ) that are responsible for bad weather.

Utu corresponds to the god Shamash in the Babylonian religion.