John Buchan, 1st Baron Tweedsmuir, Scottish-Canadian historian and politician, 15th Governor General of Canada (died 1940)

John Buchan, 1st Baron Tweedsmuir was a Scottish novelist, historian, British Army officer, and Unionist politician who served as Governor General of Canada, the 15th since Canadian Confederation.

The governor general of Canada is the federal representative of the Canadian monarch, currently King Charles III. The monarch of Canada is also sovereign and head of state of 14 other Commonwealth realms and resides in the United Kingdom. The monarch, on the advice of his or her Canadian prime minister, appoints a governor general to administer the government of Canada in the monarch's name. The commission is for an indefinite period—known as serving at His Majesty's pleasure—usually five years. Since 1959, it has also been traditional to alternate between francophone and anglophone officeholders. The 30th and current governor general is Mary Simon, who was sworn in on 26 July 2021. An Inuk leader from Nunavik, Quebec, Simon is the first Indigenous person to hold the office.