Richard Walter John Montagu Douglas Scott, 10th Duke of Buccleuch and 12th Duke of Queensberry, (born 14 February 1954), styled as Lord Eskdaill until 1973 and as Earl of Dalkeith from 1973 until 2007, is a Scottish landholder and peer. He is the Duke of Buccleuch and Queensberry, as well as Chief of Clan Scott. He is the heir male of James, Duke of Monmouth (9 April 1649 – 15 July 1685), the eldest illegitimate son of King Charles II and his mistress, Lucy Walter.