Sir James Ramsay Montagu Butler, OBE (20 July 1889 – 1 March 1975) was a British politician and academic. He was a member of parliament for Cambridge University from 1922 to 1923. He was Regius Professor of Modern History at the University of Cambridge from 1947 to 1954, and vice-master of Trinity College, Cambridge, from 1954 to 1960. He also saw military service during both the First and Second World Wars.