William Wynn Westcott (1848-1925) was an English Rosicrucian and Theosophist, Magus of the Societas Rosicruciana in Anglia, and founder of the Hermetic Order of the Golden Dawn. Westcott was a prolific writer on occult subjects, including numerous articles in theosophical periodicals, Rosicrucian pamphlets, and several books, including his 10 volume Collectanea Hermetica.