Ronald Buchanan McCallum (28 August 1898 – 18 May 1973) was a British historian. He was a fellow (and later Master) of Pembroke College,Oxford, where he taught Modern History and Politics. and was member of Tolkien's Inklings.
McCallum was also the creator of the term psephology (statistical analysis of elections).
- Asquith (biography, 1936). Great Lives Series.
- England and France, 1939-1943 (1944).
- Public Opinion and the Last Peace(1944).
- The British General Election of 1945 (1947). With Alison Readman.
- The Liberal Party from Earl Grey to Asquith (1963). Men and Ideas Series.