The Erinyes ( ih-RIN-ee-eez; sing. Erinys ih-RIN-iss, ih-RY-niss; Ancient Greek: Ἐρινύες, pl. of Ἐρινύς), also known as the Furies, and the Eumenides, were female chthonic deities of vengeance in ancient Greek religion and mythology. A formulaic oath in the Iliad invokes them as "the Erinyes, that under earth take vengeance on men, whosoever hath sworn a false oath". Walter Burkert suggests that they are "an embodiment of the act of self-cursing contained in the oath". They correspond to the Dirae in Roman mythology. The Roman writer Maurus Servius Honoratus wrote (ca. 400 AD) that they are called "Eumenides" in hell, "Furiae" on Earth, and "Dirae" in heaven. Erinyes are akin to some other Greek deities, called Poenai.

According to Hesiod's Theogony, when the Titan Cronus castrated his father, Uranus, and threw his genitalia into the sea, the Erinyes (along with the Giants and the Meliae) emerged from the drops of blood which fell on the Earth (Gaia), while Aphrodite was born from the crests of sea foam. According to variant accounts, they emerged from an even more primordial level—from Nyx ("Night"), or from a union between air and mother Earth, while in Virgil's Aeneid, they are daughters of Pluto (Hades) and Nox (Nyx). Their number is usually left indeterminate. Virgil, probably working from an Alexandrian source, recognized three: Alecto or Alekto ("endless anger"), Megaera ("jealous rage"), and Tisiphone or Tilphousia ("vengeful destruction"), all of whom appear in the Aeneid. Dante Alighieri followed Virgil in depicting the same three-character triptych of Erinyes; in Canto IX of the Inferno they confront the poets at the gates of the city of Dis. Whilst the Erinyes were usually described as three maiden goddesses, the Erinys Telphousia was usually a byname for the wrathful goddess Demeter, who was worshipped under the title of Erinys in the Arkadian town of Thelpousa.