In ancient Greek religion and mythology, Helios is the god who personifies the Sun. His name is also Latinized as Helius, and he is often given the epithets Hyperion and Phaethon. Helios is 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.

Greek mythology is the body of myths originally told by the ancient Greeks, and a genre of ancient Greek folklore, today absorbed alongside Roman mythology into the broader designation of classical mythology. These stories concern the ancient Greek religion's view of the origin and nature of the world; the lives and activities of deities, heroes, and mythological creatures; and the origins and significance of the ancient Greeks' cult and ritual practices. Modern scholars study the myths to shed light on the religious and political institutions of ancient Greece, and to better understand the nature of myth-making itself.