ION, in fabulous history, a son of Xuthus, and Creüsa, daughter of Erechtheus, who married Helice, the daughter of Selinus king of Ægiale. He succeeded to the throne of his father-in-law, and built a city, which he called Helice, on account of his wife. His subjects received from him the name of Ionians, and the country that of Ionia. See IONIA.