Vice-Admiral Peter John Douglas (30 June 1787 – 17 December 1858) was an officer of the Royal Navy who served during the French Revolutionary and Napoleonic Wars. He was born at Portsmouth on 30 June 1787, the son of Admiral . He entered the Navy on 17 January 1797 and during the next six years served on a variety of ships, including the 90-gun HMS Sandwich, commanded by his father. Prior to leaving the Franchise, he further served in the boats at the capture of the Spanish schooner Carmen, and on board that ship he succeeded in making two prizes, and in driving an armed vessel on shore.