Sir James Frederick Rees (13 December 1883 – 7 January 1967), known as Frederick Rees, was a Welsh historian and academic born in Milford Haven, who specialised in economic history and the history of Wales. From 1929 to 1949, he was Principal of University College of South Wales and Monmouthshire. He was additionally Vice-Chancellor of the University of Wales from 1935 to 1937 and also from 1944 to 1946. He had previously lectured at University College, Bangor, Queen's University Belfast, the University of Edinburgh, and the University of Birmingham.[1][2][3] He served as High Sheriff of Pembrokeshire for 1955.[4]