In Greek mythology, Hyperion (/haɪˈpɪəriən/; Greek: Ὑπερίων, romanized: Hyperíōn, 'the high one') was one of the twelve Titan children of Gaia (Earth) and Uranus (Sky) who, led by Cronus, overthrew their father Uranus and were themselves later overthrown by the Olympians. With his sister, the Titaness Theia, Hyperion fathered Helios (Sun), Selene (Moon) and Eos (Dawn).
Hyperion's son Helios was referred to in early mythological writings as Helios Hyperion (Ἥλιος Ὑπερίων, "Sun High-one"). In Homer's Odyssey, Hesiod's Theogony, and the Homeric Hymn to Demeter, the Sun is once in each work called Hyperionides (Ὑπεριωνίδης, "son of Hyperion"), and Hesiod certainly imagines Hyperion as a separate being in other writings. Ιn Βook 19 of Homer's Iliad, Homer calls the sun-god "Hyperion", a byname of the Sun, Hyperion's son. In later Greek literature, Hyperion is always distinguished from Helios; the former was ascribed the characteristics of the "God of Watchfulness, Wisdom and the Light", while the latter became the physical incarnation of the Sun. Hyperion is an obscure figure in Greek culture and mythology, mainly appearing in lists of the twelve Titans:

Of Hyperion we are told that he was the first to understand, by diligent attention and observation, the movement of both the sun and the moon and the other stars, and the seasons as well, in that they are caused by these bodies, and to make these facts known to others; and that for this reason he was called the father of these bodies, since he had begotten, so to speak, the speculation about them and their nature.

As the father of Helios, Hyperion was regarded as the “first principle” by Emperor Julian, though his relevance in Julian's notions of theurgy is unknown.

He was said to be breathtakingly beautiful. Hyperion’s name comes from he Greek for “the one who watches from above.” He is said to be the first to understand the cycles of the sun, the stars, the moon and the dawn or to even have ordered them in the first place.