Denis Arnold, CBE was a British musicologist. After work in the extramural department of The Queen's University, Belfast, he became a Lecturer in Music at the University of Hull, and from 1969 to 1975 was Professor of Music at The University of Nottingham. From 1975 he was Heather Professor of Music at Oxford University. He is best known for his editing of The New Oxford Companion to Music, and for his work on the music of Monteverdi, Marenzio and Giovanni Gabrieli. He also served as editor of Music & Letters.