Aiwass was a non-corporeal being that English occultist Aleister Crowley reported to have heard in 1904, described to be a tall, dark man in his thirties "with the face of a savage king."
According to Crowley, Aiwass appeared to him in Cairo and dictated The Book of the Law, a central aspect in the new religious movement Thelema. He later identified Aiwass as his guardian angel.