James Pounder Whitney (30 November 1857, in Marsden, West Yorkshire – 17 June 1939, in Cambridge) was a British ecclesiastical historian. Educated at King James's Grammar School, Almondbury and Owens College, Manchester, he was a foundation scholar at King's College, Cambridge, gaining firsts in the mathematics and history triposes in 1881. A fellow of King's College, he was ordained an Anglican priest in 1895. After various clerical and teaching appointment, he was professor of ecclesiastical history at King's College London from 1908 to 1918. He was Dixie Professor of Ecclesiastical History at the University of Cambridge from 1919 to 1939. He was joint editor of The Cambridge Medieval History from 1907 to 1922.