Manly Palmer Hall (March 18, 1901 – August 29, 1990) was a Canadian-born author, lecturer, astrologer, and mystic. He is best known for his 1928 work The Secret Teachings of All Ages. Hall was an active proponent of the philosophy of Theosophy, the teachings of theosophist Helena Blavatsky, and the writings of mystic Jakob Boehme. He was the founder of the Philosophical Research Society in 1934, in Los Angeles, California.