Semele (sĕm`ĭlē), in Greek mythology, mother of Dionysus, daughter of Cadmus and Harmonia. Zeus, who loved her, appeared to her as a man. Semele asked him to come to her in his divine form, but when he did the fire of his thunderbolts killed her. Zeus snatched his unborn son from her ashes and thrust him into his thigh, from which Dionysus was finally born. Later Dionysus rescued Semele from Hades and made her a goddess on Olympus.