Helios, also Helius (; Ancient Greek: Ἥλιος Hēlios; Latinized as Helius; Ἠέλιος in Homeric Greek), in ancient Greek religion and myth, is the god and personification of the Sun, often depicted in art with a radiant crown and driving a horse-drawn chariot through the sky. He was a guardian of oaths and also the god of sight.
Though Helios was a relatively minor deity in Classical Greece, his worship grew more prominent in late antiquity thanks to his identification with several major solar divinities of the Roman period, particularly Apollo and Sol. The Roman Emperor Julian made Helios the central divinity of his short-lived revival of traditional Roman religious practices in the 4th century AD.
Helios figures prominently in several works of Greek mythology, poetry, and literature, in which he is often described as the son of the Titans Hyperion and Theia and brother of the goddesses Selene (the Moon) and Eos (the Dawn).