The Office of the Prime Minister and Privy Council (French: Bureau du Premier ministre et du Conseil privé) building, formerly known as the Langevin Block (French: Édifice Langevin, IPA: [lɑ̃ʒvɛ̃]), is an office building facing Parliament Hill in Ottawa, Ontario, Canada. As the home of the Privy Council Office and Office of the Prime Minister, it is the working headquarters of the executive branch of the Canadian government. The building is a National Historic Site of Canada.