Peter Quennell (*March 9, 1905, Bickley, Kent [now in Greater London], England, † October 27, 1993, London) was an English biographer, literary historian, editor, essayist, poet, and critic.

Peter Courtney Quennell was the son of social historians Marjorie and C.H.B. Quennell. Educated at Berkhamsted Grammar School and at Balliol College, Oxford, he first practised journalism in London. 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 Tokyo University of Science and Literature in Japan. In 1944-51, he was editor of the Cornhill Magazine and from 1951 to 1979 founder-editor of History Today. In 1976, he published a volume of autobiography, entitled The Marble Foot.