Robert Sholto Johnstone Douglas (3 December 1871 – 10 March 1958), known as Sholto Douglas, or more formally as Sholto Johnstone Douglas, was a Scottish figurative artist, a painter chiefly of portraits and landscapes.
In 1895, he stood surety for the bail of Oscar Wilde.
Douglas was born in Edinburgh, a member of the aristocratic Queensberry family, part of the Clan Douglas. He was the son of A. H. Johnstone Douglas DL JP of Lockerbie (1846–1923) and his wife Jane Maitland Stewart, and the grandson of Robert Johnstone Douglas of Lockerbie, himself the son of Henry Alexander Douglas, a brother of the sixth and seventh Marquesses of Queensberry. His paternal grandmother, Lady Jane Douglas (1811–1881), was herself a daughter of Charles Douglas, 6th Marquess of Queensberry, so she was her husband's first cousin. Douglas's third cousin and contemporary John Douglas, 9th Marquess of Queensberry (1844–1900) was famous for the rules of the sport of boxing. Another cousin was Lady Florence Dixie, the war correspondent and big game hunter.
Douglas studied art in London, at the Slade School of Fine Art and also in Paris and Antwerp.