in Greek mythology, a blind Theban seer. In the Odyssey he retained his prophetic gifts even in the underworld, where the hero Odysseus was sent to consult him. At Thebes he played an active part in the tragic events concerning Laius, the king of Thebes, and his son Oedipus (q.v.). Later legend told that he lived for seven (or nine) generations, dying after the expedition of the Seven Against Thebes, and that he had once been turned into a woman as the result of killing the female of two coupling snakes; on killing the male he regained his own sex. His blindness was variously explained. One theory was that it was a punishment for revealing the secrets of the gods, which he had learned from his mother, the nymph Chariclo. Another theory was that he enraged Hera, who had contended to her husband, Zeus, that women had less pleasure in love than men, by telling her that love gave women 10 times more pleasure than it gave men. Hera thereupon struck him blind, but Zeus gave him the gifts of prophecy and longevity. A third explanation was that Tiresias was blinded by Athena because he had seen her naked.

The figure of Tiresias recurs in European literature, both as prophet and as man-woman, as in Guillaume Apollinaire's surrealist play Les Mamelles de Tirésias (first performed 1917; “The Breasts of Tiresias”) and T.S. Eliot's The Waste Land (1922).