Margaret Anchoretta Ormsby, OBC (7 June 1909 – 2 November 1996) was a noted Canadian historian, particularly concerning the History of British Columbia.
Born in Quesnel, British Columbia, she was raised in the Okanagan Valley. She enrolled at the University of British Columbia (UBC) in 1925, graduating with a Bachelor of Arts in 1929, and a Master of Arts in 1931, both in History. While pursuing her Ph.D. at Bryn Mawr College in Pennsylvania she interrupted those studies to work as a teaching assistant in history at UBC, then graduated from Bryn Mawr in 1936. She taught in the United States for the next three years, then became a lecturer at McMaster University in 1940, returning to teach at UBC in 1943. In 1955 she was appointed Professor and in 1965 became head of the university's Department of History, a position she held until her retirement in 1974.
Ormsby was chair of the Historic Sites and Monuments Board of Canada from 1960 to 1967. She received honorary doctorates from the University of Victoria and Simon Fraser University as well as UBC, and holds the Insignia of the Order of British Columbia.
Ormsby has been perhaps the most influential historian of British Columbia. In British Columbia: A History (1958) she presented a structural model that has been adopted by numerous historians and teachers. Chad Reimer says, "in many aspects, it still has not been surpassed." Ormsby posited a series of propositions that provided the dynamic to the history:
Her works include: