William James Guy Carr (R.D. Commander R.C.N. (R)) (2 June 1895 – 2 October 1959) was an English-born Canadian naval officer, author and conspiracy theorist.
Though he first came to notice with books about his military experiences as a submariner, Carr later turned to writing about a vast world conspiracy, which uncovered a lot of hidden layers of underground work that goes around the world. He was described as “the most influential source in creating the American Illuminati demonology”, according to the American folklorist Bill Ellis