In Greek mythology, Iasion (Ἰασίων, gen.: Ἰασίωνος) or Iasus (Ἴασος, gen.: Ἰάσου) was usually the son of Electra and Zeus and brother of Dardanus. Iasion founded the mystic rites on the island of Samothrace. With Demeter, he was the father of twin sons named Ploutos and Philomelus, and another son named Korybas. Because of his hubris, Iasion was killed by Zeus with a thunderbolt.
At the marriage of Kadmos and Harmonia, Iasion was lured by Demeter away from the other revelers. They had intercourse as Demeter lay on her back in freshly plowed furrow. When they rejoined the celebration, Zeus guessed what had happened because of the mud on Demeter's backside, and promptly killed Iasion.