Rohan D'Olier Butler (21 January 1917 - 30 October 1996) was an English historian and civil servant.
From 1963 to 1982 he was historical adviser to the Secretary of State for Foreign Affairs. Butler believed that historians could make a beneficial contribution to the formation of foreign policy, and he wrote extensively, especially on German and Russian issues. Sir Julian Bullard wrote that "there were few important British ministerial speeches in that period in which the argument was not strengthened and the text not embellished by a contribution from Rohan's distinctive pen".
- The Roots of National Socialism, 1783–1933 (1941).
- Choiseul: Father and Son, 1719–1754 (1980).
- Roger T. Stearn, ‘Butler, Rohan D'Olier (1917–1996)’, Oxford Dictionary of National Biography, Oxford University Press, 2004; online edn, May 2012, accessed 19 Nov 2013.