In Norse mythology, Fornjót (Old Norse: Fornjótr) was an ancient giant and king of "Gotlandi, Kænlandi and Finnlandi". His children are Ægir (the ruler of the sea), Logi (fire giant) and Kári (god of wind).
The name has often been interpreted as forn-jótr "ancient giant", and Karl Simrock (1869) because of this identified Fornjotr with the primeval giant Ymir. But it is also possible, as was suggested by Peter Erasmus Müller (1818), that it is one of a well-established group of names or titles of gods in -njótr "user, owner, possessor", which would make Fornjótr the "original owner" (primus occupans vel utens) of Norway.
Fornjót is mentioned only twice in old verse: in stanza 29 of Ynglingatal where "son of Fornjót" seems to refer to fire and in a citation in Snorri Sturluson's Skáldskaparmál:
How should the wind be periphrased? Thus: call it son of Fornjót, Brother of the Sea and of Fire, Scathe or Ruin or Hound or Wolf of the Wood or of the Sail or of the Rigging.
Thus spake Svein in the Nordrsetu-drápa:
First began to fly
Fornjót's sons ill-shapen.
Fornjót is listed as a giant (jötun) in one of the thulur sometimes included in editions of the Skáldskaparmál. This is as expected, since Fornjót's son Ægir is also identified as a giant in various sources.
In the Orkneyinga saga and in Hversu Noregr byggdist ('How Norway was settled')— both found in the Flatey Book— Fornjót appears as an ancient ruler of Gotlandi. Kænlandi and Finnlandi". He is father of three sons named Ægir or Hlér, Logi and Kári. The Hversu account says further that Ægir ruled over the seas, Logi over fire, and Kári over wind.