Lewis Grassic Gibbon (Scots pronunciation: [ˈluːis ˈɡræsɪk ˈɡibɪn]) was the pseudonym of James Leslie Mitchell (13 February 1901 – 7 February 1935), a Scottish writer. He was best known for A Scots Quair, a trilogy set in the north-east of Scotland in the early 20th century, of which all three parts have been serialised on BBC television.
 Mitchell was born into a farming family in Auchterless and raised from the age of seven in Arbuthnott, in the former county of Kincardineshire. He was educated first at the parish school and then at Mackie Academy in Stonehaven. Mitchell started working as a journalist for the Aberdeen Journal in 1917 and later for the Farmers Weekly after moving to Glasgow. During that time he was active with the British Socialist Party.
 In 1919, Mitchell joined the Royal Army Service Corps and served in Iran, India and Egypt before enlisting in the Royal Air Force in 1923. In the RAF he worked as a clerk and spent some time in the Middle East.
 When he married Rebecca Middleton (known as Ray) in 1925, they settled in Welwyn Garden City. He began writing full time in 1929, producing numerous books and shorter works under his real name and his pseudonym. He suffered an early death in 1935 from peritonitis, brought on by a perforated ulcer.
 Mitchell gained attention from his earliest attempts at fiction, notably from H. G. Wells, but it was his trilogy entitled A Scots Quair, and in particular its first book Sunset Song, with which he made his mark. A Scots Quair, with its combination of stream-of-consciousness, lyrical use of dialect, and social realism, is considered to be among the defining works of the 20th century Scottish Renaissance. It tells the story of Chris Guthrie, a young woman growing up in the north-east of Scotland in the early 20th century. All three parts of the trilogy have been turned into serials by BBC Scotland, written by Bill Craig, with Vivien Heilbron as Chris. Additionally, Sunset Song has been adapted into a film, released in 2015. Spartacus, a novel set in the famous slave revolt, is his best-known full-length work outside this trilogy.
 In 1934 Mitchell collaborated with Hugh MacDiarmid on Scottish Scene, which included three of Gibbon's short stories. His stories were collected posthumously in A Scots Hairst (1969). Possibly his best-known is "Smeddum", a Scots word which could be best translated as the colloquial term "guts". Like A Scots Quair, it is set in north-east Scotland with strong female characters. It was dramatised by Bill Craig and the BBC, as a Play for Today in 1976, along with two other short stories, "Clay" and "Greenden". Also notable is his essay The Land.
 The Grassic Gibbon Centre, attached to the local village hall, was established in Arbuthnott in 1991 to commemorate the author's life. Within it is a small museum about his life and work, as well as a café. There is a memorial to him and his wife, and other members of the Mitchell family, in the western corner of the village churchyard (parish church of Saint Ternan) of Arbuthnott Church, nowadays in Aberdeenshire.
 In 2016 Sunset Song was voted Scotland's favourite novel in the BBC Love to Read campaign. A feature article on the novel has been written by Nicola Sturgeon, who edited a recent edition.
 Glenda Norquay, "Echoes from The Mearns", reviewing The Speak of the Mearns, in Sheila G. Hearn, ed., Cencrastus No. 13, Summer 1983, pp. 54–55