in Greek mythology, a legendary king of Arcadia. Traditionally, he was an impious and cruel king who tried to trick Zeus, the king of the gods, into eating human flesh. The god was not deceived and in wrath devastated the earth with Deucalian's flood, according to Ovid's Metamorphoses, Book I. Lycaon himself was turned into a wolf.

The story of Lycaon was apparently told in order to explain an extraordinary ceremony, the Lycaea, held in honour of Zeus Lycaeus at Mount Lycaeus. According to Plato (Republic, Book VIII), this ceremony was believed to involve human sacrifice and lycanthropy (assuming the form of a wolf). The Greek traveler Pausanias implies that the rite was still practiced in the 2nd century AD.

A second Lycaon was a son of Priam, killed by Achilles in one of the most memorable scenes in Homer's Iliad (Book XXI, lines 34ff). A third Lycaon was a son of Ares who was killed by Heracles.