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 in Worthing, much to the consternation of the latter's wife Constance. On another occasion, while staying with Wilde in Brighton, Douglas fell ill with influenza and was nursed by Wilde, but failed to return the favour when Wilde himself fell ill in consequence. Instead Douglas moved to the Grand Hotel and, on Wilde's 40th birthday, sent him a letter saying that he had charged him the bill. Douglas also gave his old clothes to male prostitutes, but failed to remove from the pockets incriminating letters exchanged between him and Wilde, which were then used for blackmail. Alfred's father, the Marquess