In Greek mythology, Cranaus was the second King of Athens, succeeding Cecrops I.

He was autochthonous (born from the earth), like his predecessor. During his reign the flood of the Deucalion story was thought to have occurred. He married Pedias, a Spartan woman, with whom he had Cranae, Cranaechme, and Atthis. Atthis gave her name to Attica after dying, possibly as a young girl, although in other traditions she was the mother, by Hephaestus, of Erichthonius.

Cranaus was deposed by Amphictyon son of Deucalion, who was himself later deposed by Erichthonius.