The book "Aradia, or the Gospel of the Witches" was published by the American folklorist Charles Godfrey Leland 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. In the 20th century, the book was very influential in the development of the contemporary Pagan religion of Wicca.

Leland reported receiving some parts of the text from his primary informant on Italian witchcraft beliefs, a woman Leland referred to as "Maddalena". The rest of the material comes from Leland's research on Italian folklore and traditions, including other related material from Maddalena. Leland had been informed of the Vangelo?' s existence in 1886, but it took Maddalena eleven years to provide him with a copy.

Its fifteen chapters portray the origins, beliefs, rituals, and spells of an Italian pagan witchcraft tradition. The central figure of that religion is the goddess Aradia, who came to Earth to teach the practice of witchcraft to peasants in order for them to oppose their feudal oppressors and the Roman Catholic Church.

Leland's work remained obscure until the 1950s, when Aradia began to be examined. Scholars are divided, with some dismissing Leland's assertion regarding the origins of the manuscript, and others arguing for its authenticity as a unique documentation of folk beliefs.