William Cornwallis
 Admiral the Honourable Sir William Cornwallis GCB (10 February 1744 – 5 July 1819) was a Royal Navy officer. He was the brother of Charles Cornwallis the 1st Marquess Cornwallis British commander at the siege of Yorktown. Cornwallis took part in a number of decisive battles including the Siege of Louisbourg in 1758 and the Battle of the Saintes but is best known as a friend of Lord Nelson and as the commander-in-chief of the Channel Fleet during the Napoleonic Wars.