William James Guy Carr (R.D. Commander R.C.N. (R)) (June 2, 1895 - October 2, 1959) was a Canadian naval officer and an author. Though his accounts of wartime naval experiences found a general audience, he is best remembered today as a , "the most influential source in creating the American Illuminati demonology", according to the American folklorist Bill Ellis. Carr was also the author of famous books on the English submarine war as well as a popular lecturer.