Sir James Ramsay Montagu Butler, (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.