Aeacus (also spelled Eäcus, Greek Αἰακός, "bewailing" or "earth borne") was a mythological king of the island of Aegina in the Saronic Gulf. He was son of Zeus and Aegina, a daughter of the river-god Asopus. He was born on the island of Oenone or Oenopia, to which Aegina had been carried by Zeus to secure her from the anger of her parents, and whence this island was afterwards called Aegina.