Charles Stewart Almon Ritchie, CC (September 23, 1906 – June 7, 1995) was a Canadian diplomat and diarist. Born in Halifax, Nova Scotia, Ritchie was educated at the University of King's College, in Halifax, Nova Scotia, Pembroke College, Oxford, Harvard University, and École Libre des Sciences Politiques. He joined the Department of External Affairs in 1934 eventually becoming Canada's ambassador to West Germany (1954–1958), Permanent Representative to the United Nations (1958–1962), ambassador to the United States during the presidencies of John F. Kennedy and Lyndon Johnson (1962–1966), ambassador to the North Atlantic Council (1966–1967) and from 1967 to 1971 was Canadian High Commissioner to the United Kingdom in London.