Ildjarn was a black metal project from Norway that formed in 1991. Ildjarn recorded music until 1997 but did not officially end until 2005. The man behind Ildjarn was Vidar Vaaer, although some releases were collaborations with a musician known as Nidhogg. Ildjarn's music was a very simple and lo-fi brand of black metal, with most songs composed of basic drum patterns, a couple of riffs, and unintelligible vocals. The band's style has been compared to hardcore punk in its simplistic ferocity and short song lengths. Two Ildjarn albums were made entirely on a synthesizer.

Of all the released music, the only Ildjarn song to have its lyrics published was "Eksistensens Jeger", from the self-titled Ildjarn-Nidhogg compilation.