Herbert Edward John Cowdrey FBA (1926–2009), known as H. E. J. Cowdrey or John Cowdrey, was an English historian of the Middle Ages and an Anglican priest. He was elected priest of St Edmund Hall, University of Oxford, in 1956. He resigned the chaplaincy in 1976, but continued to teach medieval history there until 1994, when he retired and was elected emeritus fellow. He was also a Fellow of the British Academy. A leading expert on the Gregorian reforms, his most important work is the monograph Pope Gregory VII, 1073–1085, considered a masterpiece "unlikely to be surpassed".