A nisse, tomte, tomtenisse, or tonttu is a mythological creature from Nordic folklore today typically associated with the winter solstice and the Christmas season. They are generally described as being short, having a long white beard, and wearing a conical or knit cap in gray, red or some other bright colour. They often have an appearance somewhat similar to that of a garden gnome.

Nordic folklore is the folklore of Denmark, Norway, Sweden, Iceland and the Faroe Islands. It has common roots with, and has been under mutual influence with, folklore in England, Germany, the Low Countries, the Baltic countries, Finland and Sápmi. Folklore is a concept encompassing expressive traditions of a particular culture or group. The peoples of Scandinavia are heterogenous, as are the oral genres and material culture that has been common in their lands. However, there are some commonalities across Scandinavian folkloric traditions, among them a common ground in elements from Norse mythology as well as Christian conceptions of the world.