In 1962, Canada also acquired the former American Embassy at 1, Grosvenor Square in London's Mayfair district, and it was renamed Macdonald House.

Additionally, in 1874, the government of Prime Minister Alexander Mackenzie named Edward Jenkins as Canada's Agent-General in London.

Jenkins, a British Liberal Party Member of Parliament in the House of Commons of the United Kingdom, had grown up in Quebec.

The office remained the most important in Canadian diplomacy until well after World War Two, and was generally filled by political appointees rather than career diplomats.

As the high commission's role grew, it needed to expand its facilities, and on 29 June 1925, King George V and Queen Mary officiated at the dedication of Canada House on Trafalgar Square.

After years of operating from two buildings, in mid-December 2014, all the activities of the High Commission were regrouped in the expanded and fully refurbished Canada House on Trafalgar Square.