Sir Peter Courtney Quennell CBE (9 March 1905 – 27 October 1993) was an English biographer, literary historian, editor, essayist, poet, and critic.
Born in Bickley, Kent, the son of architect C. H. B. Quennell and Marjorie Quennell, he wrote extensively on social history. Educated at Berkhamsted Grammar School and at Balliol College, Oxford, he first practised journalism in London. While still at school some of his poems were selected by Richard Hughes for the anthology Public School Verse, which brought him to the attention of writers such as Edith Sitwell.
In 1922 he published his first book, Masques and Poems. This was followed by many other volumes, particularly his Four Portraits of 1945 (studies of Boswell, Gibbon, Sterne, and Wilkes), books on London and works on Baudelaire (1929), Byron (1934–35), Pope (1949), Ruskin (1949), Hogarth (1955), Shakespeare (1963), Proust (1971) and Dr Johnson (1972).
In 1930 he taught at the University of Tokyo. In 1944–51, he was editor of the Cornhill Magazine and from 1951 to 1979 founder-editor of History Today.