English: Macdonald House is a seven-storey building on Grosvenor Square in Mayfair, London that is part of the High Commission of Canada in London. Macdonald House hosts the trade and administrative sections of the High Commission, as well as the High Commissioner's official residence, while the cultural and consular functions are carried out from Canada House on Trafalgar Square. Previously, Macdonald House was the home of the American Embassy in London. It is named after Canada's first Prime Minister, Sir John A. Macdonald.