In Greek mythology, Phineus (/ˈfɪniəs, ˈfɪnjuːs/; Greek: Φινεύς, Ancient Greek: [pʰiː.neǔs]) was a king of Thrace and seer who appears in accounts of the Argonauts' voyage.
Several different versions of Phineus's parentage were presented in ancient texts. According to Apollonius of Rhodes, he was a son of Agenor, but the Bibliotheca says that other authors named his father as Poseidon (who is the father of Agenor). The Hesiodic Catalogue of Women, on the other hand, reported that Phineus was the son of Phoenix and Cassiopeia. His first wife was Cleopatra, daughter of Boreas and Oreithyia, by whom he had a pair of sons, named either Plexippus and Pandion, or Gerymbas and Aspondus, or Polydector and (?) Polydophus, or Parthenius and Crambus. His second wife Idaea, daughter of Dardanus (less commonly Eidothea, sister of Cadmus, or Eurytia), deceived him into blinding these sons, a fate Phineus himself would suffer. By his second wife, or by a Scythian concubine, Phineus had two more sons, Mariandynus and Thynus. According to some sources, he also had two daughters, Eraseia and Harpyreia.