Dr. Major Harold Wigmore McGill (December 21, 1879 – July 3, 1961) was a Canadian physician and provincial politician from Alberta.

His parents were Edward McGill, whose family had emigrated from Ireland to Canada in 1819, and Henrietta Wigmore, also of Irish descent.

[4]:xviii Henrietta was a former school teacher, and had once circumnavigated the globe, travelling to New Zealand for a teaching job and later returning to Canada.

McGill's eldest brother, Herbert, took over the running of the family farm until his younger siblings had completed their basic schooling.

[2] Harold went overseas to fight in World War I, and his wife Emma moved to England to serve as a nurse.