William Paton Ker (usually referred to as "W. P. Ker"; 30 August 1855 - 17 July 1923) was a Scottish literary scholar and essayist.
He was born in Glasgow in 1855. He studied at Glasgow Academy, the University of Glasgow and Balliol College, Oxford.
He was appointed to a fellowship at All Souls College, Oxford in 1879. He became Professor of English Literature and History at the University College of South Wales, Cardiff in 1883; and moved to University College London as Quain Professor in 1889. He was the Oxford Professor of Poetry from 1920 to his death whilst hill-climbing in Europe. A W. P. Ker Memorial Lecture is held at Glasgow University in his honour.
He is referred to repeatedly in J. R. R. Tolkien's essay Beowulf: The Monsters and the Critics. W. H. Auden's discovery of Ker was a turning point:
- "... what good angel lured me into Blackwell's one afternoon and, from such a wilderness of volumes, picked out for me the essays of W. P. Ker? No other critic whom I have subsequently read could have granted me the same vision of a kind of literary All Souls Night in which the dead, the living and the unborn writers of every age and tongue were seen as engaged upon a common, noble and civilizing task. No other could have so instantaneously aroused in me a fascination with prosody, which I have never lost."
- Epic and Romance: Essays on Medieval Literature (1897); second edition, 1908.
- The Dark Ages 
- Sturla the Historian (1906)
- Tennyson (1909)
- English literature; medieval (1912) — also known as Medieval English literature (ISBN 9780198880431 ISBN 0-19-888043-X)
- Two Essays (1918)
- Sir Walter Scott (1919)
- The Art of Poetry (1923)
- Form And Style In Poetry (1928)
- On Modern Literature
- Collected Essays (1968) edited by Charles Whibley
- ^ W. H. Auden, The Dyer's hand and other essays, "Making, Knowing, and Judging,", p. 42.