In Greek mythology the Graeae (meaning "old women", "grey ones", or "grey witches"; alternatively spelled Graiai, also called the Grey Sisters, were three sisters in Greek mythology who shared one eye and one tooth among them. Their names were Deino, Enyo, and Pemphredo.

They were one of several trios of archaic goddesses in Greek mythology. The Graeae were daughters of the sea-deities Phorcys and Ceto. Thus, they were among thePhorcydes, all of which were either aquatic (sea-based) or chthonic (earth-based) deities. The Graeae were sisters to the Gorgons. The Graeae took the form of old grey-haired women; though, at times poets euphemistically described them as "beautiful." In other legends they are described as being half-swan.

Their age was so great that a human childhood for them was hardly conceivable. Their names were reported as well-clad Pemphredo and saffron-robed Enyo. Pseudo-Apollodorus added Deino as a third. Hyginus adds a fourth, Persis or Perso.

They shared one eye and one tooth, which they took turns using. By stealing their eye while they were passing it amongst themselves, the hero Perseus forced them to tell the whereabouts of the three objects needed to kill Medusa (in other versions the whereabouts of Medusa herself), by ransoming their shared eye for the information. One might compare the Graeae with the three spinners of Destiny; the northern European Norns; or the Baltic goddess Laima and her two sisters; though all are distinct trios.