English biographer, literary critic, and educator, best known for his discerning, sympathetic, and elegantly written studies of many literary figures.

Lord Cecil was the younger son of the 4th marquess of Salisbury. Educated at Oxford, he was a fellow of Wadham College (1924–30) and of New College (1939–69). He served as Goldsmiths' professor of English literature at Oxford University from 1948 to 1969.

Among his subjects for biography were the poet William Cowper (The Stricken Deer, 1929), Jane Austen (1935), Lord Melbourne (The Young Melbourne, 1939), Hardy, the Novelist (1943), the 17th-century letter writer Dorothy Osborne, the poet Thomas Gray (Two Quiet Lives, 1948), and the writer and caricaturist Sir Max Beerbohm (Max, 1964). Library Looking-glass (1975) was a personal anthology, tracing his intellectual history.