Seiðr (sometimes anglicized as seidhr, seidh, seidr, seithr, seith, or seid) is an Old Norse term for a type of sorcery which was practiced in Norse society during the Late Scandinavian Iron Age. Connected with Norse religion, its origins are largely unknown, although it gradually eroded following the Christianization of Scandinavia. Accounts of seiðr later made it into sagas and other literary sources, while further evidence has been unearthed by archaeologists. Various scholars have debated the nature of seiðr, some arguing that it was shamanic in context, involving visionary journeys by its practitioners.

Seiðr (sometimes anglicized as seidhr, seidh, seidr, seithr, seith, or seid) is an Old Norse term for a type of sorcery which was practiced in Norse society during the Late Scandinavian Iron Age. Connected with Norse religion, its origins are largely unknown, although it gradually eroded following the Christianization of Scandinavia. Accounts of seiðr later made it into sagas and other literary sources, while further evidence has been unearthed by archaeologists. Various scholars have debated the nature of seiðr, some arguing that it was shamanic in context, involving visionary journeys by its practitioners.