Stevenson was born Robert Lewis Balfour Stevenson, in Edinburgh, Scotland, on November 13, 1850; when he was around 18 years old he changed the spelling of 'Lewis' to 'Louis'. His father was Thomas Stevenson, and grandfather was Robert Stevenson, both distinguished lighthouse keepers and inventors, as was his great-grandfather. It was from this side of the family that he inherited his love of adventure, joy of the sea and for the open road. His maternal grandfather, Lewis Balfour, was a professor of moral philosophy and a minister, and it was in his house that he spent the greater part of his boyhood. "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." From his mother, Margaret Balfour, he inherited weak lungs (perhaps tuberculosis), that kept him constantly in "the land of the counterpane" during the winter, where his nurse spent long hours by his bedside reading from the Bible, and lives of the old Covenanters. During the summer he was encouraged to play outside proving to be a wild and care-free child and by the age of eleven his health had improved so that his parents prepared him for the University of Edinburgh by attending Edinburgh Academy, planning for him to follow his father as a lighthouse keeper. During this period he read widely and enjoyed especially Shakespeare, Walter Scott, John Bunyan and The Arabian Nights.

He entered the University of Edinburgh at age seventeen but soon discovered he had neither the scientific mind nor physical endurance to succeed as an engineer. When his father took him for a voyage he found - instead of being interested in lighthouse construction - that his mind was teeming with wonderful romances about the coast and islands which they visited. Although his father was stern, he finally allowed him to decide upon a career in literature.