In Greek mythology, Omphale (Ancient Greek: Ὀμφάλη) was a daughter of Iardanus, either a king of Lydia, or a river-god. Omphale was queen of the kingdom of Lydia in Asia Minor; according to Bibliotheke she was the wife of Tmolus, the oak-clad mountain king of Lydia; after he was gored to death by a bull, she continued to reign on her own.
Diodorus Siculus provides the first appearance of the Omphale theme in literature, though Aeschylus was aware of the episode. The Greeks did not recognize her as a goddess: the undisputed etymological connection with omphalos, the world-navel, has never been made clear. In her best-known myth, she is the mistress of the hero Heracles during a year of required servitude, a scenario that offered writers and artists opportunities to explore sexual roles and erotic themes.
In one of many Greek variations on the theme of penalty for "inadvertent" murder, for his murder of Iphitus, the great hero Heracles, whom the Romans identified as Hercules, was, by the command of the Delphic Oracle Xenoclea, remanded as a slave to Omphale for the period of a year, the compensation to be paid to Eurytus, who refused it. The theme, inherently a comic inversion of sexual roles, is not fully illustrated in any surviving text from Classical Greece. Plutarch, in his vita of Pericles, 24, mentions lost comedies of Kratinos and Eupolis, which alluded to the contemporary capacity of Aspasia in the household of Pericles, and to Sophocles in The Trachiniae it was shameful for Heracles to serve an Oriental woman in this fashion, but there are many late Hellenistic and Roman references in texts and art to Heracles being forced to do women's work and even wear women's clothing and hold a basket of wool while Omphale and her maidens did their spinning. Omphale even wore the skin of the Nemean Lion and carried Heracles' olive-wood club. Unfortunately no full early account survives, to supplement the later vase-paintings.