In Greek mythology, Tyche ("luck") (Roman equivalent: Fortuna) was the presiding tutelary deity that governed the fortune and prosperity of a city, its destiny. Increasingly during the Hellenistic period cities had their own specific iconic version of Tyche, wearing a mural crown, that is a crown like the walls of the city. In literature, she might be given various genealogies, as a daughter of Hermes and Aphrodite, or considered as one of the Oceanids, daughters of Oceanus and Tethys or Zeus Pindar. She was connected with Nemesis and Agathos Daimon ("good spirit").

Tyche appears on many coins of the Hellenistic period in the three centuries before the Christian era, especially from cities in the Aegean.

In medieval art, she was depicted as carrying a cornucopia, an emblemmatic ship's rudder and the wheel of fortune, or she may stand on the wheel, presiding over the entire circle of fate.