In Greek mythology, Idmon was an Argonaut seer. Allegedly a son of Apollo, he had Abas (or Ampycus) as his mortal father. His mother was Asteria, daughter of Coronus, or Cyrene, or else Antianeira, daughter of Pheres. By Laothoe he had a son Thestor. Idmon foresaw his own death in the Argonaut expedition, but joined anyway. During the outbound voyage of Argo, a boar killed him in the land of the Mariandyni, in Bithynia.