In Norse mythology, Dökkálfar (Old Norse: Dǫkkálfar "Dark Elves"; singular Dökkálfr) and Ljósálfar (Old Norse for "Light Elves", singular Ljósálfr) are two contrasting types of elves; the former dwell within the earth and are most swarthy, while the latter live in Álfheimr, and are "fairer than the sun to look at". The Dökkálfar and the Ljósálfar are attested in the Prose Edda, written in the 13th century by Snorri Sturluson, and in the late Old Norse poem Hrafnagaldr Óðins. Scholars have produced theories about the origin and implications of the dualistic concept.
In the Prose Edda, the Dökkálfar and the Ljósálfar are attested in chapter 17 of the book Gylfaginning. In the chapter, Gangleri (the king Gylfi in disguise) asks the enthroned figure of High what other "chief centres" there are in the heavens outside of the spring Urðarbrunnr. Gangleri responds that there are many fine places in heaven, including a place called Álfheimr (Old Norse 'Elf Home' or 'Elf World'). High says that the Ljósálfar live in Álfheimr, while the Dökkálfar dwell underground and look—and particularly behave—quite unlike the Ljósálfar. High describes the Ljósálfar as "fairer than the sun to look at", while the Dökkálfar are "blacker than pitch".
As chapter 17 continues, Gangleri asks what will protect the beautiful hall of Gimlé, previously described as "the southernmost end of heaven", when the fires of Surtr "burn heaven and earth" (Ragnarök). High responds that there are in fact other heavens. The first called Andlàngr, he says, is "south of and above this heaven of ours" and "we believe" Gimlé is located in the third heaven "still further above that one", Víðbláinn. High adds that "we believe it is only light-elves who inhabit these places for the time being".