Phineus was a king of the region of Thrace in Greek mythology, as well as a seer. He appeared in the myth of Jason and the Argonauts, on their way to retrieve the Golden Fleece from the mythical land of Colchis. There are various accounts as to who his parents may have been; some attribute Agenor or Poseidon as his father, while others say he was the child of Phoenix and Cassiopeia. He was initially married to Cleopatra, while later he married Idaea. He had a number of children with his wives.
According to different sources, he was blinded, an event that happened as a punishment for either blinding his own sons; giving Phrixus directions; or revealing the future to mankind. As extra punishment, he was tormented by the Harpies, which defiled his food whenever he tried to eat. When Argo, the ship of Jason, arrived in Thrace, Phineus described his torment to the hero. Among the Argonauts were Phineus' brothers-in-law, the Boreads, who were told by Phineus that they were fated to help him. The Boreads feared the wrath of the gods if they tried to help him, but Phineus reassured them that no harm would come to them. So, when the Harpies appeared and ate Phineus' food, the Boreads chased them until Iris appeared in front of them. The goddess told them that they should not hunt the Harpies any more as they would no longer torment Phineus. The Boreads returned to the Argonauts, and Phineus informed them how to safely pass through the Symplegades, in order to reach Colchis.