John Dalrymple (fl. 1744 - d. 1798) was an officer of the Royal Navy. He became a fellow of the Royal Society. He entered the Royal Navy as a Captain's servant aboard HMS Alderney. He passed his examinations for promotion to lieutenant in 1744. He commanded a sloop in 1757; and he was promoted to post-captain in 1758. He was captain of HMS Winchester in 1762. He was promoted to the rank of rear-admiral of the white in 1787, and advanced to vice-admiral in 1793. He was commander-in-chief at the Nore from 11 May 1794, flying his flag aboard HMS Sandwich. He was promoted to the rank of admiral of the blue in 1795.