In Greek mythology, Cepheus is the name of two rulers of Ethiopia, grandfather and grandson.
Cepheus son of Belus was the son of Belus and Achiroe, making him the brother of Danaus, King of Libya, and Aegyptus, King of Egypt. He had a wife named Iope and a son who he named Agenor after his paternal uncle (Agenor the father of Cadmus and Europa). This Cepheus, through his son Agenor, became the grandfather of Cepheus son of Agenor the more well-known Cepheus, who features in the Perseus legend as the husband of Cassiopeia and father of Andromeda, and whose brother Phineus expected to marry Andromeda. These two Aethiopian kings named Cepheus separated by a couple of generations were apparently not intended to be confused as one and the same person by the mythographers.