William Henry Walter Montagu Douglas Scott, 6th Duke of Buccleuch & 8th Duke of Queensberry KG KT PC JP DL (9 September 1831 5 November 1914) was a Scottish Member of Parliament and peer. He was the paternal grandfather of HRH Princess Alice, Duchess of Gloucester, and the maternal great-grandfather of HRH Prince William of Gloucester and HRH Prince Richard, Duke of Gloucester. He was a paternal great-great-grandfather to Sarah, Duchess of York.