Gelon, a ruler of Syracuse, born in Gela in Sicily, died about 478 B. C. He served as commander of the cavalry under Hippocrates, tyrant of Gela; on whose death, the people revolting against his sons, Gelon supported the latter, but tinally set them aside and assumed the chief power himself (491). Called to the assistance of the Gamori, the landed aristocracy of Syracuse, then expelled by the revolted slaves and the popular party, he contrived to become master of that city (about 485), appointed his brother Hiero governor of Gela, and by degrees extended his influence and power over all Sicily. He won the affections of the Syracusans by mildness, by the protection of arts and sciences, and by the aggrandizement of the city, for which purpose he even destroyed Camarina and other towns, and transplanted their inhabitants thither, as well as half the population of Gela. When Xerxes was threatening the invasion of Greece, the Lacedaemonians and Athenians invoked the assistance of Gelon. According to Herodotus, he offered to furnish 200 triremes, nearly 30,000 soldiers, and corn for the whole Grecian army so long as the war should last, provided he was made commander-in-chief. The condition being rejected, Gelon sent an ambassador to Delphi, with rich gifts, and orders to greet and acknowledge Xerxes if victorious.

Herodotus, however, also mentions that the Syracusans give a different version of the affair, which vindicates the character of Gelon and the policy of the Syracusans in not assisting Greece. They were fully occupied at home, for the Carthaginians at this juncture invaded Sicily with a great army. Gelon completely defeated them at Himera (480), on the same day, according to Herodotus, on which the Greeks won the victory of Salamis, but according to Diodorus, on the day of the battle of Thermopylae. He now proposed to resign his power and restore popular liberty, but the offer was rejected in the assembly, and his exhibition of magnanimity was rewarded by the title of king, which he accepted and bore till his death. The Syracusans erected, against his will, a splendid tomb to his memory, and honored him as a hero. When Timoleon, 130 years afterward, sought to destroy all vestiges of the tyrants, the statue of Gelon was excepted. His brother Hiero was his successor.