In 1946 he was appointed as Governor General of Canada by King George VI, on the recommendation of Prime Minister of Canada William Lyon Mackenzie King, to replace the Earl of Athlone as viceroy, and he occupied the post until he was succeeded by Vincent Massey in 1952. Alexander proved to be enthusiastic about the Canadian wilderness and popular with Canadians. He was the last Governor General before Adrienne Clarkson who was not born in Canada as well as the last Governor General to be a peer.