Dr. Sir William Beatty MD FRS (April 1773–25 March 1842) was an Irish who served in the Royal Navy. Born in Derry, Ireland, he joined as a surgeon's mate in 1791 at the age of 18. He is best known as the Ship's Surgeon on the HMS Victory during the Battle of Trafalgar, at which he witnessed the death of Admiral Horatio Nelson, and for authoring an account of that battle - The Death of Lord Nelson.