In Norse mythology, Sif is a goddess associated with earth. Sif is attested in the Poetic Edda, compiled in the 13th century from earlier traditional sources, and the Prose Edda, written in the 13th century by Snorri Sturluson, and in the poetry of skalds. In both the Poetic Edda and the Prose Edda, Sif is the wife of the god Thor and is known for her golden hair.
In the Prose Edda, Sif is named as the mother of the goddess Þrúðr by Thor and of Ullr with a father whose name is not recorded. The Prose Edda also recounts that Sif once had her hair shorn by Loki, and that Thor forced Loki to have a golden headpiece made for Sif, resulting in not only Sif's golden tresses but also five other objects for other gods.
Scholars have proposed that Sif's hair may represent fields of golden wheat, that she may be associated with fertility, family, wedlock and/or that she is connected to rowan, and that she may appear or be referenced in the Old English poem Beowulf.