Sir John Harman (c. 1625 – 11 October 1673) was an English naval officer who was captain and then admiral during the three Anglo-Dutch wars between 1652 and 1673.He fought in several major battles.He was captain of the flagship of the Duke of York, the future King James II of England, in the Battle of Lowestoft in 1665.The Dutch were defeated but escaped when Harman reduced sail due to a mistaken order.There was a great scandal over this incident, but Harman was completely absolved and was promoted to rear admiral.He played an epic role in the St. James's Day Battle in 1666.In 1667 he destroyed a French fleet off Martinique, then captured the French and Dutch colonies in South America.He died while still active as an admiral during the Third Anglo-Dutch War.