Fimbulheimen is a mountain range in Queen Maud Land, Antarctica. It stretches from Jutulstraumen by 1ð west of Carsten Borchgrevink Ice at 18ð east, about 200 km from the ice edge. Fimbulheimen is thus between Maudheim Plateau and Sør-Rondane.
Dronning Maud's highest mountain, Jøkulkyrkja (elevation 3148 m), is located in Mühlig-Hofmann Mountains in Fimbulheimen. The name comes from Fimbulvetr, the harsh winter immediately preceding Ragnarok in Norse mythology.
A number of smaller ranges and mountain areas constitutes Fimbulheimen, from west to east:
The Norwegian research station Troll is located by Jutulsessen Mountain west in Fimbulheimen, while the ornithological field station Tor is about 100 km further east at Svarthamaren Mountain in Mühlig-Hofmann Mountains.
Large parts of the area were mapped by the Norwegian Antarctic Expedition 1956-60. The Norwegian Polar Institute has published twelve map sheets of Fimbulheimen in scale 1:250 000.