Sir William Empson (27 September 1906 – 15 April 1984) was an English literary critic and poet.

He is sometimes praised as the greatest English literary critic after Samuel Johnson and William Hazlitt, and widely influential for his practice of closely reading literary works, fundamental to the New Critics. Jonathan Bate has claimed that the three greatest English Literary critics of the 18th, 19th and 20th centuries are, respectively, Johnson, Hazlitt and Empson, "not least because they are the funniest".

Empson has been styled a "critic of genius" by Sir Frank Kermode, who qualified his praise by identifying willfully perverse readings of certain authors; and Harold Bloom has stated that Empson is among a handful of critics who matter most to him, because of their force and eccentricity. Empson's bluntness led to controversy both during his life and after his death, and a reputation in part also as a "licensed buffoon" (Empson's own phrase).

William Empson's poetry occupies a central place in 20th-century literature. Acclaimed as the brilliant author of Seven Types of Ambiguity, published when he was only 24, Empson has been applauded for the dazzling intelligence and emotional passion of his poems. T. S. Eliot praised the "brain power" and "intense feeling" of his poetry; F. R. Leavis hailed him as the first true successor to John Donne. Robert Lowell told Empson: "I think you are the most intelligent poet writing in our language and perhaps the best. I put you with Hardy and Graves and Auden and Philip Larkin".Empson's poems have a range of themes from metaphysics to melancholy, social climbing to political satire, love to loss. Above all, he was stimulated by the implications of modern science, which he called "the only fertile part of the contemporary mind".This volume brings together for the first time all the poems that Empson published in his lifetime and several more discovered since his death. Drawing on unpublished papers, interviews, readings, and broadcasts, John Haffenden's introduction and annotations identify manuscript sources, allusions, and intertexts. The volume also includes Empson's own notes, which he regarded as a vital complement to the poetry. Sir William Empson was educated at Winchester and Cambridge and taught at Tokyo University, Peking National University, and the University of Sheffield, where he was chair of English literature from 1952 until his retirement in 1971. He was knighted in 1979 and died in London in 1984.