Odin (Old Norse: Óðinn) is the chief deity of the Norse pantheon and one of the most complex figures in Germanic religion. Attested across a wide range of primary sources, he is a god of wisdom, war, death, poetry, and magic. Known by well over a hundred heiti (bynames) — forty-nine of which are enumerated in the Eddic poem Grímnismál alone — Odin is portrayed as a peripatetic figure who wanders the nine worlds in disguise, typically wearing a wide-brimmed hat and grey cloak and carrying his spear Gungnir. He rules from his hall Valhöll (Valhalla) as lord of the Æsir and receives half of those slain in battle — the einherjar — who train there in preparation for Ragnarök.

Odin’s relentless pursuit of wisdom is a defining characteristic across the primary sources. According to the Eddic poem Hávamál, Odin hung himself upon the world-tree Yggdrasil for nine nights, wounded by his own spear and offered to himself, in order to gain knowledge of the runes. The Prose Edda’s Gylfaginning records that he sacrificed one of his eyes at the well of Mímir in exchange for a drink of its waters, gaining cosmological insight. Two ravens, Huginn (Thought) and Muninn (Memory), fly throughout the world each day and return to report all they have witnessed, as described in Grímnismál. Odin is also associated with seiðr, a form of Norse divinatory magic culturally coded as ergi (unmanly) — a tension acknowledged in the Eddic poem Lokasenna, where Loki rebukes Odin for practicing it, and addressed directly in Ynglinga saga.

In war and death, Odin functions as both inciter of conflict and receiver of the slain. The valkyries act as his agents on the battlefield, choosing which warriors fall and escorting them to Valhöll. His role as a deity of hanging and sacrificial death is underscored by the account of the great festival at the temple of Uppsala given by Adam of Bremen in his Gesta Hammaburgensis (c. 1070s), which describes a nine-day gathering every nine years during which males of many species — including humans — were hanged in a sacred grove adjoining the temple. While this account comes from a Christian source and must be treated with critical caution, the motif of hanging sacrifice to Odin is internally consistent with Hávamál’s self-hanging episode and with broader references in skaldic poetry.

Odin’s cult was widespread across the Germanic and Scandinavian worlds. Tacitus, writing in the first century CE, identifies a supreme Germanic deity as Mercurius, whom scholars generally equate with the Proto-Germanic *Wōðanaz — the ancestor of Odin — based on shared attributes including psychopomp functions and an association with wisdom and the dead. The equation of Wednesday with Wōdnesdæg (Woden’s Day) in Old English, corresponding to the Latin dies Mercurii, further supports this interpretatio romana. The Uppsala temple complex is considered a principal cult center; Odin is listed there alongside Thor and Freyr as one of three primary deities in Adam of Bremen’s account.