In Greek mythology, Ares (Ancient Greek: , modern Greek Άρης [pron. "áris"]) is the son of Zeus (ruler of the gods) and Hera. Though often referred to as the Olympian god of warfare, he is more accurately the god of savage warfare, or bloodlust, or slaughter personified.

The Romans identified him as Mars, the Roman god of war and agriculture (whom they had inherited from the Etruscans), but among them, Mars stood in much higher esteem (also see Athena.).

Among the Hellenes, Ares was always distrusted. Though Ares' half-sister Athena was also considered to be a war deity, Athena's stance was that of strategic warfare while Ares' tended to be the unpredictable violence of war. His birthplace and true home was placed far off, among the barbarous and warlike Thracians (Iliad 13.301; Ovid, Ars Amatoria, II.10;), to whom he withdrew after his affair with Aphrodite was revealed.

"Ares" remained an adjective and epithet in Classical times: Zeus Areios, Athena Areia, even Aphrodite Areia. In Mycenaean times, inscriptions attest to Enyalios, a name that survived into Classical times as an epithet of Ares. Vultures and dogs, which both prey upon carrion in the battlefield, are sacred to him.