Quiller-Couch was born in the town of Bodmin, Cornwall, by the union of two ancient local families, the Quiller family and the Couch family, and was the third in a line of intellectuals from the Couch family. His younger sisters Florence Mabel and Lilian M. were also writers and folklorists. His father, Dr. Thomas Quiller Couch (d. 1884), was a noted physician, folklorist and historian. He married Mary Ford and lived at 63, Fore Street, Bodmin, until his death in 1884. His grandfather, Jonathan Couch, was an eminent naturalist, also a physician, historian, classicist, apothecary, and illustrator (particularly of fish). His son, Bevil Brian Quiller-Couch, was a war hero and poet, whose romantic letters to his fiancée, the poet May Wedderburn Cannan, were published in Tears of War. He also had a daughter, Foy Felicia, to whom Kenneth Grahame inscribed a first edition of his The Wind in the Willows attributing Quiller-Couch as the inspiration for the character Ratty.
He was educated at Newton Abbot Proprietary College, at Clifton College, and Trinity College, Oxford, where he took a First in Classical Moderations (1884) and a Second in Greats (1886). From 1886 he was for a brief time a classical lecturer at Trinity. After some journalistic experience in London, mainly as a contributor to the Speaker, he settled in 1891 at Fowey in Cornwall.
In Cornwall he was an active political worker for the Liberal Party. He was knighted in 1910, and in 1928 was made a Bard of the Cornish cultural society Gorseth Kernow, adopting the Bardic name Marghak Cough ('Red Knight'). He was Commodore of the Royal Fowey Yacht Club from 1911 until his death.
Quiller-Couch died at home in May 1944, after being slightly injured by a jeep near his home in Cornwall in the preceding March. He is buried in Fowey's parish church of St. Fimbarrus.
In 1887, while he was attending Oxford, he published Dead Man's Rock, a romance in the style of Robert Louis Stevenson's Treasure Island, and later Troy Town (1888), a comic novel set in a fictionalised version of his home town Fowey, and The Splendid Spur (1889). Quiller-Couch was well known for his story "The Rollcall of the Reef", based on the wreck of HMS Primrose during 1809 on the Cornish coast. He published during 1896 a series of critical articles, Adventures in Criticism, and in 1898 he published a completion of Robert Louis Stevenson's unfinished novel, St. Ives.
From his Oxford time he was known as a writer of excellent verse. With the exception of the parodies entitled Green Bays (1893), his poetical work is contained in Poems and Ballads (1896). In 1895 he published an anthology from the 16th- and 17th-century English lyricists, The Golden Pomp, followed in 1900 by the Oxford Book of English Verse, 1250–1900. Later editions of this extended the period of concern to 1918 and it remained the leading general anthology of English verse until Helen Gardner's New Oxford Book of English Verse appeared in 1972.
In 1910 he published The Sleeping Beauty and other Fairy Tales from the Old French. He was the author of a number of popular novels with Cornish settings (collected edition as 'Tales and Romances', 30 vols. 1928–29).
He was appointed King Edward VII Professor of English Literature at the University of Cambridge in 1912, and retained the chair for the rest of his life. Simultaneously he was elected to a Fellowship of Jesus College, which he held until his death. His inaugural lectures as the professor of English literature were published as the book On the Art of Writing. His rooms were on staircase C, First Court, and known as the 'Q-bicle'. He supervised the beginnings of the English Faculty there — an academic diplomat in a fractious community. He is sometimes regarded as the epitome of the school of English literary criticism later modified by his pupil F. R. Leavis.
Alistair Cooke was a notable student of Quiller-Couch and Nick Clarke's semi-official biography of Cooke features Quiller-Couch prominently, noting that he was regarded by the Cambridge establishment as "rather eccentric" even by the university's standards.
Quiller-Couch was a noted literary critic, publishing editions of some of Shakespeare's plays (in the New Shakespeare, published by Cambridge University Press, with Dover Wilson) and several critical works, including Studies in Literature (1918) and On the Art of Reading (1920). He edited a companion to his verse anthology: The Oxford Book of English Prose, which was published in 1923. He left his autobiography, Memories and Opinions, unfinished; it was nevertheless published in 1945.
His Book of English Verse is often quoted by John Mortimer's fictional character Horace Rumpole.
Castle Dor, a re-telling of the Tristan and Iseult myth in modern circumstances, was left unfinished at Quiller-Couch's death and was completed many years later by Daphne du Maurier. As she wrote in the Sunday Telegraph on April 1962, she began the job with considerable trepidation, at the request of Quiller-Couch's daughter and "in memory of happy evenings long ago when 'Q' was host at Sunday supper".
He features as a main character, played by Leo McKern, in the 1992 BBC television feature The Last Romantics. The story focuses on his relationship with his protégé, F. R. Leavis, and the students.
His Cambridge inaugural lecture series, published as On the Art of Writing, is the source of the popular writers' adage "murder your darlings".
He is mentioned briefly in The Well of Lost Plots by Jasper Fforde as one of the few authors with a name beginning with the letter "Q".
It is Quiller-Couch who originated the saying "kill your darlings":Dead Man's Rock (1887)
The Astonishing History of Troy Town (1888)
The Splendid Spur (1889)
The Blue Pavilions (1891)
Ia, and other tales (1896)
St Ives (1898), completing an unfinished novel by Robert Louis Stevenson.
Noughts and Crosses: Stories Studies and Sketches (1898)
The Ship of Stars (1899)
The Westcotes (1902)
Hetty Wesley (1903) (This was based on the life of the poet Mehetabel Wesley Wright)
The Adventures of Harry Revel (1903)
Fort Amity (1904)
The Shining Ferry (1905)
The Mayor of Troy (1906)
Sir John Constantine (1906)
Poison Island (1907)
True Tilda (1909)
A collected edition of Q's fiction appeared as Tales and Romances (30 volumes, 1928–29).Green Bays (1893)
Poems and Ballads (1896)
The Golden Pomp, a procession of English lyrics from Surrey to Shirley (1895)
Adventures in Criticism (1896)
Oxford Book of English Verse, 1250–1900 also online (1900)
From a Cornish Window (1906)
English Sonnets (1910)
The Sleeping Beauty and other Fairy Tales from the Old French (1910)
The Oxford Book of Ballads (1911)
In Powder and Crinoline: Old Fairy Tales Retold (1913)
On the Art of Writing (1916)
Notes on Shakespeare's Workmanship (1917)
Studies in Literature First Series and Second Series (1918)
On the Art of Reading (1920)
The Oxford Book of Victorian Verse (1922)
Oxford Book of English Prose (1923)
Memories and Opinions (unfinished, published 1945)