In Canada, a lieutenant governor (/lɛfˈtɛnənt/; French [masculine]: lieutenant-gouverneur, or [feminine]: lieutenant-gouverneure) is the viceregal representative in a provincial jurisdiction of the Canadian monarch and head of state, Queen Elizabeth II, who resides predominantly in her oldest realm, the United Kingdom. On the advice of his or her prime minister, the Governor General of Canada appoints the lieutenant governors to carry out most of the monarch's constitutional and ceremonial duties for an unfixed period of time—known as serving at His Excellency's pleasure—though five years is the normal convention. Similar positions in Canada's three territories are termed Commissioners and are representatives of the federal government, however, not the monarch directly.
The offices have their roots in the 16th and 17th century colonial governors of New France and British North America, though the present incarnations of the positions emerged with Canadian Confederation and the British North America Act in 1867, which defined the viceregal offices as the "Lieutenant Governor of the Province acting by and with the Advice the Executive Council thereof." However, the posts still ultimately represented the government of Canada (that is, the Governor-General-in-Council) until the ruling in 1882 of the Lord Watson of the Judicial Committee of the Privy Council in the case of Maritime Bank v. Receiver-General of New Brunswick, whereafter the lieutenant governors were recognized as the direct representatives of the monarch. Per the Constitution Act, 1982, any constitutional amendment that affects the Crown, including the Offices of the lieutenant governors, requires the unanimous consent of each provincial legislature as well as the federal parliament.