John Roland Seymour Phillips is a British historian. He did a Doctor of Philosophy degree at the University of London in 1967, on the subject of the 14th-century Earl of Pembroke, Aymer de Valence. Later he published a book on the same subject. Phillips was head of the department of medieval history, at the University College Dublin. Today he is professor emeritus at that school. In 2010, Phillips contributed a volume on King Edward II to the Yale English Monarchs series.