In Norse mythology, Muspelheim (Old Norse: Múspellsheimr), also called Muspell (Old Norse: Múspell), is a realm of fire. This realm is one of the Nine Worlds, ruled by Surtr with his consort Sinmara in some accounts. The denizens of Muspelheim were usually referred to as the Eldjötnar ("fire giants") in Norse tradition, though they were also identified by other epithets in Eddic poetry, such as the Múspellssynir (or Múspellsmegir — "sons of Muspell") and the Rjúfendr (from rjúfa — "to break, tear asunder", Destroyers of Doomsday). Both of these terms sometimes described an entirely separate mythological species that dwelled alongside or in place of the eldjötnar within this fiery realm. Muspelheim is fire; and the land to the North, Niflheim, is ice. The two mixed and created water from the melting ice in Ginnungagap. The sun and the stars originate from Muspelheim.
In the midst of this clash and din the heavens are rent in twain, and the sons of Muspell come riding through the opening. Surtr rides first, and before him and after him flames burning fire. He has a very good sword, which shines brighter than the sun. As they ride over Bifrost it breaks to pieces, as has before been stated. The sons of Muspel direct their course to the plain which is called Vigrid.... The sons of Muspel have there effulgent bands alone by themselves.
The etymology of "Muspelheim" is uncertain, but may come from Mund-spilli, "world-destroyers", "wreck of the world".
Múspelheim appears in the science fiction novel Resonance: Ragnarok: Volume Three (Kindle Location 3488) by John Meaney
Muspelheim is mentioned in the anime Sword Art Online II during a quest taking place in Jötunheim. Yui - an AI in the show - expresses her concern that even if they complete the quest and defeat Þrymr, the flame giants of Muspelheim will take over Alfheim by burning down Yggdrasil.
In the Video Game Valkyrie Profile, Muspelheim is mentioned within the magic words that compose the great Magic "Ifreet Caress": "I invoke the rites of fiery Muspelheim, now give up thy soul to inferno's embrace! Ifreet Caress!"
In the videogame La Mulana 2, Múspelheim (spelled "Muspellheim") is an area within the ruins Eg'Lana and is known as the "Blazing Frost Canopy", a land that's both frozen and on fire. This technically makes it both Múspelheim and Niflheim in one.
In the Japanese light novel Mahouka Koukou no Rettousei, Muspelheim is the name of a magic spell that creates a field where immense heat, capable of creating plasma, is generated.
In the Amon Amarth song "Destroyer of the Universe", Muspelheim is mentioned in the first verse.
In the Unleashed song "The Bolt Thrower" the titular character in the song was "Forged in the fires of Muspelheim."
In the 2014 video game Bayonetta 2 Muspelheim serves as the location of challenge rooms within portals found throughout levels, however the realm is not represented like it is described in Norse Mythology but instead like the typical depictions of Judeo-Christian "Heaven" and "Hell".
In Heroine's Quest, Muspell (actually eldjötnar) appear as enemies.