In Greek mythology, King Oenomaus of Pisa was the son of Ares by Sterope (or by Harpina daughter of Phliasian Asopus) and father of Hippodamia.

Pelops wanted to marry Hippodamia of Pisa. Oenamaus had pursued a thirteen suitors of Hippodamia and killed them all after beating them in a chariot race (because Poseidon or Ares had given him swift or winged horses). He did this because he loved her himself or, alternatively, because a prophecy claimed he would be killed by her son. Pelops (or alternatively, Hippodamia herself) convinced Myrtilus (by promising him half of Oenomaus kingdom), Oenomaus' charioteer to remove the linchpins attaching the wheels to the chariot. Oenomaus died as a result. In memory of Oenomaus, the Olympic Games were created (or alternativily the Olympic Games were in celebration of Pelops victory). Pelops then killed Myrtilus because he didn't want to share the credit for winning the chariot race, or because Myrtilus had attempted to rape Hippodamia. As Myrtilus died, he cursed Pelops. This was the source of the curse that haunted future generation of Pelops' children, including Atreus, Thyestes, Agamemnon, Aegisthus, Menelaus and Orestes.

Oenomaus' chariot race was one legendary origin of the Olympic Games.

Alternative: Oinomaos, Oenamaus