John Graham Lake was a Canadian-American leader in the Pentecostal movement that began in the early 20th century, and is known as a faith healer, missionary, and with Thomas Hezmalhalch, co-founder of the Apostolic Faith Mission of South Africa.
Through his 1908–19 African missionary work, Lake played a decisive role in the spread of Pentecostalism in South Africa, the most successful southern African religious movement of the 20th century.
After completing his missionary work in Africa, Lake evangelized for 20 years, primarily along the west coast of the United States setting up “healing rooms” and healing campaigns and establishing churches.