William Douglas, 1st Baron Drumlanrig

Sir William Douglas, 1st of Drumlanrig (died 1427) was the illegitimate son of James Douglas, 2nd Earl of Douglas. He fought against the English in the Hundred Years' War in France, where he was killed in action in 1427. He married Elizabeth Stewart, daughter of Sir Robert Stewart of Durisdeer, and had one son, William Douglas, 2nd of Drumlanrig.