Lang was born in Selkirk, the eldest of the eight children of John Lang, town clerk of Selkirk, and his wife Jane Plenderleath Sellar, daughter of Patrick Sellar, factor to the first duke of Sutherland. On 17 April 1875 he married Leonora Blanche Alleyne, youngest daughter of C. T. Alleyne of Clifton and Barbados.

He was educated at Selkirk grammar school, and at the Edinburgh Academy, St Andrews University and at Balliol College, Oxford, where he took a first class in the final classical schools in 1868, becoming a fellow and subsequently honorary fellow of Merton College. As a journalist, poet, critic and historian, he soon made a reputation as one of the most able and versatile writers of the day.

He died of angina pectoris at the Tor-na-Coille Hotel in Banchory, Banchory, survived by his wife. He was buried in the cathedral precincts at St Andrews.

Folklore and anthropology

Lang is now chiefly known for his publications on folklore, mythology, and religion. The earliest of his publications is Custom and Myth (1884). In Myth, Ritual and Religion (1887) he explained the "irrational" elements of mythology as survivals from more primitive forms. Lang's Making of Religion was heavily influenced by the 18th century idea of the "noble savage": in it, he maintained the existence of high spiritual ideas among so-called "savage" races, drawing parallels with the contemporary interest in occult phenomena in England. His Blue Fairy Book (1889) was a beautifully produced and illustrated edition of fairy tales that has become a classic. This was followed by many other collections of fairy tales, collectively known as Andrew Lang's Fairy Books. Lang examined the origins of totemism in Social Origins (1903).

Psychical research

Lang was one of the founders of "Psychical Research" and his other writings on anthropology include The Book of Dreams and Ghosts (1897), Magic and Religion (1901) and The Secret of the Totem (1905). He served as President of the Society for Psychical Research in 1911.

Classical scholarship

He collaborated with S.H. Butcher in a prose translation (1879) of Homer's Odyssey, and with E. Myers and Walter Leaf in a prose version (1883) of the Iliad, both still noted for their archaic but attractive style. He was a Homeric scholar of conservative views. Other works include Homer And The Study Of Greek found in Essays In Little (1891), Homer and the Epic (1893); a prose translation of The Homeric Hymns (1899), with literary and mythological essays in which he draws parallels between Greek myths and other mythologies; and Homer and his Age (1906).

Historian

Lang's writings on Scottish history are characterised by a scholarly care for detail, a piquant literary style, and a gift for disentangling complicated questions. The Mystery of Mary Stuart (1901) was a consideration of the fresh light thrown on Mary, Queen of Scots, by the Lennox manuscripts in the University Library, Cambridge, approving of her and criticising her accusers.

He also wrote monographs on The Portraits and Jewels of Mary Stuart (1906) and James VI and the Gowrie Mystery (1902). The somewhat unfavourable view of John Knox presented in his book John Knox and the Reformation (1905) aroused considerable controversy. He gave new information about the continental career of the Young Pretender in Pickle the Spy (1897), an account of Alestair Ruadh MacDonnell, whom he identified with Pickle, a notorious Hanoverian spy. This was followed by The Companions of Pickle (1898) and a monograph on Prince Charles Edward (1900). In 1900 he began a History of Scotland from the Roman Occupation (1900). The Valet's Tragedy (1903), which takes its title from an essay on Dumas's Man in the Iron Mask, collects twelve papers on historical mysteries, and A Monk of Fife (1896) is a fictitious narrative purporting to be written by a young Scot in France in 1429-1431.

Other writings

Lang's earliest publication was a volume of metrical experiments, The Ballads and Lyrics of Old France (1872), and this was followed at intervals by other volumes of dainty verse, Ballades in Blue China (1880, enlarged edition, 1888), Ballads and Verses Vain (1884), selected by Mr Austin Dobson; Rhymes à la Mode (1884), Grass of Parnassus (1888), Ban and Arrière Ban (1894), New Collected Rhymes (1905).

Lang was active as a journalist in various ways, ranging from sparkling "leaders" for the Daily News to miscellaneous articles for the Morning Post, and for many years he was literary editor of Longman's Magazine; no critic was in more request, whether for occasional articles and introductions to new editions or as editor of dainty reprints.

He edited The Poems and Songs of Robert Burns (1896), and was responsible for the Life and Letters (1897) of JG Lockhart, and The Life, Letters and Diaries (1890) of Sir Stafford Northcote, 1st Earl of Iddesleigh. Lang discussed literary subjects with the same humour and acidity that marked his criticism of fellow folklorists, in Books and Bookmen (1886), Letters to Dead Authors (1886), Letters on Literature (1889), etc.

To 1884

• St Leonards Magazine. 1863. This was a reprint of several articles that appeared in the St Leonards Magazine that Lang edited at St Andrews University. Includes the following Lang contributions: Pages 10—13, Dawgley Manor; A sentimental burlesque; Pages 25—26, Nugae Catulus; Pages 27—30, Popular Philosophies; pages 43—50 are ‘Papers by Eminent Contributors’, seven short parodies of which six are by Lang.
• The Ballads and Lyrics of Old France (1872)
• The Odyssey Of Homer Rendered Into English Prose (1879) translator with Samuel Henry Butcher
• Aristotle's Politics Books I. III. IV. (VII.). The Text of Bekker. With an English translation by W. E. Bolland . Together with short introductory essays by A. Lang To page 106 are Lang's Essays, pp. 107—305 are the translation. Lang's essays without the translated text were later published as The Politics of Aristotle. Introductory Essays. 1886.
• The Folklore of France (1878)
• Specimens of a Translation of Theocritus. 1879. This was an advance issue of extracts from ‘Theocritus, Bion and Moschus rendered into English prose’
• XXII Ballades in Blue China (1880)
• Oxford. Brief historical & descriptive notes (1880)
• 'Theocritus Bion and Moschus. Rendered into English Prose with an Introductory Essay. 1880.
• Notes by Mr A. Lang on a collection of pictures by Mr J. E.Millais R.A. exhibited at the Fine Arts Society Rooms. 148 New Bond Street. 1881.
• The Library: with a chapter on modern illustrated books. 1881.
• The Black Thief. A new and original drama (Adapted from the Irish) in four acts.(1882)
• Helen of Troy, her life and translation. Done into rhyme from the Greek books. 1882.
• The Most Pleasant and Delectable Tale of the Marriage of Cupid and Psyche (1882) with William Aldington
• The Iliad of Homer, a prose translation (1883) with Walter Leaf and Ernest Myers
• Custom and Myth (1884)
• The Princess Nobody: A Tale of Fairyland (1884)
• Ballads and Verses Vain (1884) selected by Austin Dobson
• Rhymes à la Mode (1884)
• Much Darker Days. By A. Huge Longway. (1884)
• Household tales; their origin, diffusion, and relations to the higher myths. [1884]. Separate pre-publication issue of the "introduction" to Bohn's edition of Grimm's Household tales.

1885-1889

• That Very Mab (1885) with May Kendall
• Books and Bookmen (1886)
• Letters to Dead Authors (1886)
• In the Wrong Paradise (1886) stories
• The Mark of Cain (1886) novel
• Lines on the inaugural meeting of the Shelley Society. Reprinted for private distribution from the Saturday Review of 13 March 1886 and edited by Thomas Wise (1886)
• La Mythologie Traduit de L’Anglais par Léon Léon Parmentier. Avec une préface par Charles Michel et des Additions de l'auteur. (1886) Never published as a complete book in English, although there was a Polish translation. The first 170 pages is a translation of the article in the ‘Encyclopaedia Britannica’. The rest is a combination of articles and material from ‘Custom and Myth’.
• Almae matres (1887)
• He (1887 with Walter Herries Pollock) parody
• Aucassin and Nicolette (1887)
• Myth, Ritual and Religion (2 vols., 1887)
• Johnny Nut and the Golden Goose. Done into English from the French of Charles Deulin (1887)
• Grass of Parnassus. Rhymes old and new. (1888)
• Perrault's Popular Tales (1888)
• Gold of Fairnilee (1888)
• Pictures at Play or Dialogues of the Galleries (1888) with W. E. Henley
• Prince Prigio (1889)
• The Blue Fairy Book (1889) (illustrations by Henry J. Ford)
• Letters on Literature (1889)
• Lost Leaders (1889)
• Ode to Golf. Contribution to On the Links; being Golfing Stories by various hands (1889)
• The Dead Leman and other tales from the French (1889) translator with Paul Sylvester

1890—1899

• The Red Fairy Book (1890)
• The World's Desire (1890) with H. Rider Haggard
• Old Friends: Essays in Epistolary Parody (1890)
• The Strife of Love in a Dream, Being the Elizabethan Version of the First Book of the Hypnerotomachia of Francesco Colonna (1890)
• The Life, Letters and Diaries of Sir Stafford Northcote, 1st Earl of Iddesleigh (1890)
• Etudes traditionnistes (1890)
• How to Fail in Literature (1890)
• The Blue Poetry Book (1891)
• Essays in Little (1891)
• On Calais Sands (1891)
• The Green Fairy Book (1892)
• The Library with a Chapter on Modern English Illustrated Books (1892) with Austin Dobson
• William Young Sellar (1892)
• The True Story Book (1893)
• Homer and the Epic (1893)
• Prince Ricardo of Pantouflia (1893)
• Waverley Novels (by Walter Scott), 48 volumes (1893) editor
• St. Andrews (1893)
• Montezuma's Daughter (1893) with H. Rider Haggard
• Kirk's Secret Commonwealth (1893)
• The Tercentenary of Izaak Walton (1893)
• The Yellow Fairy Book (1894)
• Ban and Arrière Ban (1894)
• Cock Lane and Common-Sense (1894)
• Memoir of R. F. Murray (1894)
• The Red True Story Book (1895)
• My Own Fairy Book (1895)
• Angling Sketches (1895)
• A Monk of Fife (1895)
• The Voices of Jeanne D'Arc (1895)
• The Animal Story Book (1896)
• The Poems and Songs of Robert Burns (1896) editor
• The Life and Letters of John Gibson Lockhart (1896) two volumes
• The Nursery Rhyme Book (1897)
• The Miracles of Madame Saint Katherine of Fierbois (1897) translator
• The Pink Fairy Book (1897)
• A Book of Dreams and Ghosts (1897)
• Pickle the Spy (1897)
• Modern Mythology (1897)
• The Companions of Pickle (1898)
• The Arabian Nights Entertainments (1898)
• The Making of Religion (1898)
• Selections from Coleridge (1898)
• Waiting on the Glesca Train (1898)
• The Red Book of Animal Stories (1899)
• Parson Kelly (1899) Co-written with A. E. W. Mason
• The Homeric Hymns (1899) translator
• The Works of Charles Dickens in Thirty-four Volumes (1899) editor

1900—1909

• The Grey Fairy Book (1900)
• Prince Charles Edward (1900)
• Parson Kelly (1900)
• The Poems and Ballads of Sir Walter Scott, Bart (1900) editor
• A History of Scotland - From the Roman Occupation (1900—1907) four volumes
• Notes and Names in Books (1900)
• Alfred Tennyson (1901)
• Magic and Religion (1901)
• Adventures Among Books (1901)
• The Violet Fairy Book (1901)
• The Mystery of Mary Stuart (1901, new and revised ed., 1904)
• The Book of Romance (1902)
• The Disentanglers (1902)
• James VI and the Gowrie Mystery (1902)
• Notre-Dame of Paris (1902) translator
• The Young Ruthvens (1902)
• The Gowrie Conspiracy: the Confessions of Sprott (1902) editor
• The Crimson Fairy Book (1903)
• Lyrics (1903)
• Social England Illustrated (1903) editor
• The Story of the Golden Fleece (1903)
• The Valet's Tragedy (1903)
• Social Origins (1903) with Primal Law by James Jasper Atkinson
• The Snowman and Other Fairy Stories (1903)
• Stella Fregelius: A Tale of Three Destinies (1903) with H. Rider Haggard
• The Brown Fairy Book (1904)
• Historical Mysteries (1904)
• The Secret of the Totem (1905)
• New Collected Rhymes (1905)
• John Knox and the Reformation (1905)
• The Puzzle of Dickens's Last Plot (1905)
• The Clyde Mystery. A Study in Forgeries and Folklore (1905)
• Adventures among Books (1905)
• Homer and His Age (1906)
• The Red Romance Book (1906)
• The Orange Fairy Book (1906)
• The Portraits and Jewels of Mary Stuart (1906)
• Life of Sir Walter Scott (1906)
• The Story of Joan of Arc (1906)
• New and Old Letters to Dead Authors (1906)
• Tales of a Fairy Court (1907)
• The Olive Fairy Book (1907)
• Poets' Country (1907) editor, with Churton Collins, W. J. Loftie, E. Hartley Coleridge, Michael Macmillan
• The King over the Water (1907)
• Tales of Troy and Greece (1907)
• The Origins of Religion (1908) essays
• The Book of Princes and Princesses (1908)
• Origins of Terms of Human Relationships (1908)
• Select Poems of Jean Ingelow (1908) editor
• Three Poets of French Bohemia (1908)
• The Red Book of Heroes (1909)
• The Marvellous Musician and Other Stories (1909)
• Sir George Mackenzie King's Advocate, of Rosehaugh, His Life and Times (1909)

1910—1912

• The Lilac Fairy Book (1910)
• Does Ridicule Kill? (1910)
• Sir Walter Scott and the Border Minstrelsy (1910)
• The World of Homer (1910)
• The All Sorts of Stories Book (1911)
• Ballades and Rhymes (1911)
• Method in the Study of Totemism (1911)
• The Book of Saints and Heroes (1912)
• Shakespeare, Bacon and the Great Unknown (1912)
• A History of English Literature (1912)
• In Praise of Frugality (1912)
• Ode on a Distant Memory of Jane Eyre (1912)
• Ode to the Opening Century (1912)

Posthumous

• Highways and Byways in The Border (1913) with John Lang
• The Strange Story Book (1913) with Mrs. Lang
• The Poetical Works (1923) edited by Mrs. Lang, four volumes
• Old Friends Among the Fairies: Puss in Boots and Other Stories. Chosen from the Fairy Books (1926)
• Tartan Tales From Andrew Lang (1928) edited by Bertha L. Gunterman
• From Omar Khayyam (1935)