Leighton Goldie McCarthy, (December 15, 1869 – October 3, 1952) was a Canadian politician and diplomat. Born in Walkerton, Ontario and called to the Ontario Bar in 1892 before he was elected to the House of Commons of Canada in 1898 as an independent representing the riding of Simcoe North. He was re-elected in 1900 and 1904. He was defeated in 1911 when he ran as a Liberal. He was President of the Canada Life Assurance Company. In 1941, he was appointed to the Queen's Privy Council for Canada. From 1941 to 1944, he was the first Canadian ambassador to the United States (before the position was called Envoy Extraordinary and Minister Plenipotentiary). McCarthy was a lawyer before and after this political and diplomatic appointment but ended his practice in 1946. McCarthy moved to Toronto and built a house at 45 Walmer Road in 1932 and died here in 1952. The McCarthy home was sold to the University of Toronto in 1953.