In Norse mythology, King Thrym ("uproar") of the Jotuns (frost giants) stole Mjollnir, Thor's hammer, to extort the gods into giving him Freya as his wife. His kingdom was called Jotunheim.

Thrym (or Trym) was foiled in his scheme by the knowledge of Heimdall, the cunning of Loki and the sheer violence of Thor. In fact, mighty Thor, son of Odin, later killed Thrym, his sister, and all of his giant kin, which had been present at the wedding reception.

The poem Trymskvida gives the details of how Thor got his hammer back, but does not tell who inherited Trym's fabulous treasures, given that all of his kin were killed.

There is also a Saturnian moon, Thrymr, which was originally named Thrym.