This is a list of ambassadors of the United States to Canada. The ambassador is the head of the Embassy of the United States in Ottawa. Prior to 1943, the head of the U.S. diplomatic mission to Canada bore the title of Envoy Extraordinary and Minister Plenipotentiary. The U.S. mission to Canada was upgraded from legation to embassy status in June 1943; Ray Atherton was the first chief of mission to hold ambassadorial rank. List See also Ambassadors of the United States Canada–United States relations Embassy of the United States, Ottawa Foreign relations of Canada List of ambassadors of Canada to the United States References United States Department of State: Background notes on Canada External links United States Department of State: Chiefs of Mission for Canada United States Department of State: Canada United States Embassy in Ottawa Canada United States