Aradia, or the Gospel of the Witches is a book composed by the American folklorist Charles Godfrey Leland that was published in 1899. It contains what he believed was the religious text of a group of pagan witches in Tuscany, Italy that documented their beliefs and rituals. Historians and folklorists have disputed the existence of such a group. During the 20th century, the book was influential in the development of the contemporary Pagan religion of Wicca.

Charles Godfrey Leland was an American humorist and folklorist, born in Philadelphia, Pennsylvania. He was educated at Princeton University and in Europe.