The Triskel is an ancient Celtic symbol representing all trinities. Three is seen as a magical number by many ancient cultures, especially the Celts. Many of their gods appeared in triple-form. One belief is that doing something thrice makes it so. In numerology, three represents creative power and gheshtalt (when two things become more than the sum of their parts).

As a Celtic symbol, the triskelion, usually consisting of spirals, but also the "horned triskelion", sometimes plays a role in Celtic groups and, rarely, can be seen in use by Germanic neopagan groups. The spiral triskelion is one of the primary symbols of Celtic Re-constructionist Paganism, and also used by some Wiccans. Celtic Re-constructionists use the symbol to represent a variety of triplicates in their cosmology and theology; it is also a favored symbol due to its association with the god Manannán Mac Lir. Wicca is syncretic in nature and often aesthetically adopts symbolism from various cultures, particularly Celtic symbolism. It is less commonly used amongst Germanic neopagan groups due to the non-Germanic origins of the symbol; use by Germanic groups may be due to confusion or association with Norse symbols with triple symmetries, like the Valknut, the Triquetra, or the symbol found on the Snoldelev Stone.