The Pennsic War is an annual American medieval and Renaissance camping event held by the Society for Creative Anachronism (SCA), a "war" between two large regional SCA groups: the Kingdom of the East and the Middle Kingdom. It is the single largest annual SCA event, with more than 10,000 people attending each year, from as far as China, South Korea, Sweden, Germany, France, Italy, Greece, and Australia.

The Society for Creative Anachronism (SCA) is an international living history group with the aim of studying and recreating mainly Medieval European cultures and their histories before the 17th century. A quip often used within the SCA describes it as a group devoted to the Middle Ages "as they ought to have been", choosing to "selectively recreate the culture, choosing elements of the culture that interest and attract us". Founded in 1966, the non-profit educational corporation has over 20,000 paid members as of 2020 with about 60,000 total participants in the society, including members and non-member participants.