Phlegyas (Greek: Φλεγύας), son of Ares and Chryse or Dotis, was king of the Lapiths in Greek mythology. He was the father of Ixion and Coronis, one of Apollo's lovers. While pregnant with Asclepius, Coronis fell in love with Ischys, son of Elatus. When a crow informed Apollo of the affair, he sent his sister Artemis to kill Coronis. Apollo rescued the baby though and gave it to the centaur Chiron to raise. Phlegyas was irate and torched the Apollonian temple at Delphi, causing Apollo to kill him.
In the Aeneid of Virgil, Phlegyas is shown tormented in the Underworld, warning others not to despise the Gods. In the Thebaid of Statius, Phlegyas is entombed in a rock by Megaera (one of the Furies) and starves in front of an eternal feast.
In the Divine Comedy poem Inferno, Phlegyas ferries Virgil and Dante across the river Styx, which is portrayed as a marsh where the wrathful and sullen lie. Phlegyas was the mythical ancestor of the Phlegyans.