Henry Stanley Ferns, or Harry Ferns, H S Ferns (16 December 1913 – 19 February 1992), was a Canadian born historian of Anglo-Argentine relations
Ferns is chiefly remembered for the critical biography of Canadian prime minister William Lyon Mackenzie King that he co-authored with Bernard Ostry, The Age of Mackenzie King: The Rise of the Leader (Heinemann, 1955).