Eridu (Sumerian: "Mighty Place" or "Place of the Prince") is an ancient Sumerian city in what is now Tell Abu Shahrain, Dhi Qar Governorate, Iraq.

Eridu was considered the earliest city in southern Mesopotamia, and is one of the oldest cities in the world.

Located 12 km southwest of Ur, Eridu was the southernmost of a conglomeration of Sumerian cities that grew about temples, almost in sight of one another.

In Sumerian mythology, Eridu was originally the home of Enki, who was considered to have founded the city, later known by the Akkadians as Ea.

His temple was called E-Abzu, as Enki was believed to live in Abzu ("Deep Ocean"), a subterranean body of water from which all life was believed to stem.