Patrick McDouall-Crichton, 6th Earl of Dumfries (15 October 1726 – 7 April 1803) was a Scottish peer. In 1768 he inherited the Earldom of Dumfries from his maternal uncle William Dalrymple-Crichton, and on his death was succeeded by his grandson, John, Lord Mount Stuart, grandson of the 1st Marquess of Bute and later 2nd Marquess of Bute.