Lord Francis Douglas Marquess of Queensberry; a younger brother, Lord Archibald Edward Douglas (1850–1938), who became a clergyman; and a younger brother and sister, the twins Lord James Douglas (d. 1891) and Lady Florence Douglas (1855–1905), who married Sir Alexander Beaumont Churchill Dixie, 11th Baronet. He was an uncle of Oscar Wilde's lover Lord Alfred Douglas, and a younger brother of John Douglas, 9th Marquess of Queensberry. In 1858, Douglas's father, Lord Queensberry, died in what was reported as a shooting accident, but his death was widely believed to have been suicide. In 1862, his mother, Lady Queensberry, converted to Roman Catholicism and
Lord Alfred Douglas sister "Florrie" (Lady Florence Douglas) and was heartbroken when she married a baronet, Sir Alexander Beaumont Churchill. In 1885, Lord James tried to abduct a young girl, and after that became ever more manic; in 1888, he made a disastrous marriage. Separated from Florrie, James drank himself into a deep depression, and in 1891 committed suicide by cutting his throat. Another of his uncles, Lord Francis Douglas (1847–1865) had died in a climbing accident on the Matterhorn. His uncle Lord Archibald Edward Douglas (1850–1938), on the other hand, became a clergyman. Alfred Douglas's aunt, Lord James's twin Lady Florence Dixie