Lascelles Abercrombie (9 January 1881 – 27 October 1938) was a British poet and literary critic, one of the "Dymock poets". After the First World War he worked as a professor of English literature in a number of English universities, writing principally on the theory of literature.

Abercrombie was born in Ashton upon Mersey, Sale, Cheshire. He was educated at Malvern College, and at Owens College, Manchester.

Before the First World War, he lived for a time at Dymock in Gloucestershire, part of a community of poets, including Robert Frost, and often visited by Rupert Brooke, and Edward Thomas. The Dymock poets were included among the "Georgian poets", and Abercrombie's poetry was included in four of the five volumes of Georgian Poetry (edited by Edward Marsh, 1912–1922). During the pre-War years, he earned his living reviewing books, and started his poetry writing. His first book, Interludes and Poems (1908), was followed by Mary and the Bramble (1910) and the play Deborah, and later by Emblems of Love (1912) and Speculative Dialogues (1913). His critical works include An Essay Towards a Theory of Art (1922), and Poetry, Its Music and Meaning (1932). The Poems of Lascelles Abercrombie (1930) was followed by The Sale of St. Thomas (1930), a dramatic poem.

During World War I, he served as a munitions examiner, after which he was appointed to the first lectureship in poetry at the University of Liverpool. In 1922 he was appointed Professor of English at the University of Leeds in preference to J. R. R. Tolkien, with whom he shared, as author of The Epic (1914), a professional interest in heroic poetry. In 1929 he moved on to the University of London, and in 1935 to the prestigious Goldsmiths' Readership at the University of Oxford, where he was elected as a Fellow of Merton College. He wrote a series of works on the nature of poetry, including The Idea of Great Poetry (1925) and Romanticism (1926). He published several volumes of original verse, largely metaphysical poems in dramatic form, and a number of verse plays. Abercrombie also contributed to Georgian Poetry and several of his verse plays appeared in New Numbers (1914). His poems and plays were collected in 'The Poems of Lascelles Abercrombie' (1930).

Lascelles Abercrombie suffered in his later years from serious diabetes, and died in London in 1938, aged 57.

At the end of the Second World War, it was discovered that, despite his death, Abercrombie's name had been mistakenly included in "The Black Book" or Sonderfahndungsliste G.B. list of Britons who were to be arrested in the event of a Nazi invasion of Britain.

His mother, born Sarah Ann Heron, was a broad minded woman and had a sense of humour. His father, William Abercrombie, was a stock broker by profession and had the habit of reading books of eminent writers. Lascelles inherited his father's habit. ' Nous ' was the nickname used by his family members. (Source : The British Academy - https://www.thebritishacademy.ac.uk - pp no394 to 421) Abercrombie was the brother of architect and noted town planner Patrick Abercrombie. In 1909 he married Catherine Gwatkin (1881–1968) of Grange-over-Sands. They had 4 children, a daughter and three sons. Two of the sons achieved prominence, David Abercrombie as a phonetician and Michael Abercrombie as a cell biologist. The latter's son Nicholas Abercrombie is a sociologist. A grandson, Jeffrey Cooper, produced an admirable bibliography of his grandfather, with brief but important notes, while a great-grandson is author Joe Abercrombie.

Arthur Ransome dedicated his second children's adventure novel Swallowdale to Lascelles's daughter Elizabeth. He was a close friend of her father, Lascelles, who was often his walking/hiking companion during the 1900/1910s. He had previously dedicated his 1909 anthology, The Book of Friendship to Lascelles Abercrombie.