He was educated at Harrow School and later served as a private secretary to the Liberal politician Lord Rosebery. Thanks to Rosebery's patronage, on 22 June 1893 he was raised to the Peerage of the United Kingdom as Baron Kelhead, of Kelhead in the County of Dumfries. This provided him with a seat in the House of Lords, which was denied to his father, whose titles were all in the Peerage of Scotland.
Drumlanrig's father served in Parliament from 1872 to 1880 as a representative peer, but in 1880 he refused, as an atheist, to take the religious oath of allegiance to the Queen. He was not allowed to take his seat and was never again chosen as representative peer by the Scottish nobles. His son's accession to Parliament as the 1st Baron Kelhead precipitated a bitter dispute between them and also between Queensberry and Lord Rosebery, who became Prime Minister in 1894.
In October 1894, eighteen months after his ennoblement, Drumlanrig died in what may have been a hunting accident suicide or a homicide. He was unmarried and his younger brother Lord Percy Douglas became heir to his father's titles.
It was speculated at the time, and evidence suggests that Drumlanrig may have had a homosexual relationship with Rosebery, and further, that Queensberry had threatened to expose the Prime Minister's supposed proclivities if his government did not vigorously prosecute Oscar Wilde in the affair stemming from Wilde's relationship with Francis Douglas's younger brother Lord Alfred Douglas. Rosebery was, by most accounts, happily married until the death of his wife in 1890, though gossip that Rosebery was homosexual or bisexual was indeed widespread. Queensberry believed that, as he phrased it to Lord Alfred in a letter, "Snob Queers like Rosebery" had corrupted his sons, and held the Prime Minister indirectly responsible for Drumlanrig's death.