Henry Maria Robert Egmont Mayr-Harting (born 6 April 1936) is a British medieval ecclesiastical historian. He was Regius Professor of Ecclesiastical History in the University of Oxford and Lay Canon of Christ Church, Oxford, from 1997 until 2003.
Mayr-Harting was born on 6 April 1936 in Prague to a Viennese couple, Herbert Mayr-Harting and Anna Mayr-Harting, née Münzer, who had a distinguished career as a bacteriologist in Bristol, England.
He was educated at Douai School and Merton College, Oxford (BA 1957, MA 1961, DPhil 1961, DD 2004).
Mayr-Harting was Lecturer in Medieval History at the University of Liverpool 1960–68. He then returned to Oxford to become Fellow and Tutor in Medieval History at St Peter's College from 1968 until 1997, when he was appointed Fellow Emeritus. From 1976 until 1997 he was also Lecturer in Medieval History at Merton College. He was Slade Professor of Fine Art for the academic year 1987–88 and in 1993 he was named University Reader in Medieval History. In 1997 he became the first Roman Catholic and the first layperson to be appointed Regius Professor of Ecclesiastical History in the University of Oxford and consequently he became the first Lay Canon of Christ Church Cathedral. He retired from these positions in 2003.