Hrungnir was a giant in Norse mythology, slain by the god Thor with his hammer Mjollnir. The account is documented in the Skáldskaparmál, in the Younger Edda by Snorri Sturluson.

Prior to his demise, Hrungnir engaged in a wager with Odin in which Odin staked his head betting on his horse, Sleipnir being faster than the steed of the giant's Gullfaxi . After the race, which Sleipnir won, he was invited into Valhalla, but became drunk and abusive. The gods called on Thor to battle with Hrungnir, and defeated him.

See also: Valknut.