Robert Louis Balfour Stevenson (13 November 1850 – 3 December 1894) was a Scottish novelist, poet, essayist and travel writer. Stevenson was greatly admired by many authors, including Jorge Luis Borges, Ernest Hemingway, Rudyard Kipling, Marcel Schwob, Vladimir Nabokov, J. M. Barrie, and G. K. Chesterton, who said of him that he "seemed to pick the right word up on the point of his pen, like a man playing spillikins".

Stevenson was born Robert Lewis Balfour Stevenson at 8 Howard Place, Edinburgh, Scotland, on 13 November 1850, to Thomas Stevenson (1818–1887), a leading lighthouse engineer, and his wife Margaret, born Margaret Isabella Balfour (1829–1897). Lighthouse design was the family profession: Thomas's own father was the famous Robert Stevenson, and his maternal grandfather, Thomas Smith, and brothers Alan and David were also among those in the business. On Margaret's side, the family were gentry, tracing their name back to an Alexander Balfour, who held the lands of Inchrye in Fife in the fifteenth century. Her father, Lewis Balfour (1777–1860), was a minister of the Church of Scotland at nearby Colinton, and Stevenson spent the greater part of his boyhood holidays in his house. "Now I often wonder", says Stevenson, "what I inherited from this old minister. I must suppose, indeed, that he was fond of preaching sermons, and so am I, though I never heard it maintained that either of us loved to hear them."

Both Balfour and his daughter had a "weak chest" and often needed to stay in warmer climates for their health. Stevenson inherited a tendency to coughs and fevers, exacerbated when the family moved to a damp and chilly house at 1 Inverleith Terrace in 1853. The family moved again to the sunnier 17 Heriot Row when Stevenson was six, but the tendency to extreme sickness in winter remained with him until he was eleven. Illness would be a recurrent feature of his adult life, and left him extraordinarily thin. Contemporary views were that he had tuberculosis, but more recent views are that it was bronchiectasis or even sarcoidosis.