The Occult World is a book originally published in 1881 in London; it was compiled by a member of the Theosophical Society A. P. Sinnett. It was the first theosophical work by the author; according to Goodrick-Clarke, this book "gave sensational publicity to Blavatsky's phenomena" and the letters from the mahatmas, and drew the attention of the London Society for Psychical Research.