Admiral Sir John Harman (c. 1625 – 11 October 1673) was an English officer of the Royal Navy, who served first under the Commonwealth, then Charles II following the 1660 Stuart Restoration.

At the start of the Second Anglo-Dutch War, he was captain of HMS Gloucester, the flagship used by James, Duke of York at Lowestoft in 1665.

The English won a clear victory, but Harman was criticised for his alleged failure to pursue the beaten Dutch fleet.

Promoted Admiral in August 1673, he succeeded Prince Rupert of the Rhine as commander-in-chief of the fleet, but died shortly afterwards on 11 October.

[1] Born around 1625, he is thought to be the brother of Philip Harman, who worked as an upholsterer in London, and was related by marriage to the author Samuel Pepys.

[2] Harman first appears in official records towards the end of the First English Civil War in 1646, as commander of the Falcon, an Armed merchantman contracted by the Parliamentarian navy.

Shortly after the First Anglo-Dutch War began in July 1652, he was appointed captain of the Welcome, a Fourth-rate warship captured from the Dutch, that fought at the Battle of the Kentish Knock in September.

[1] Although the war did not formally end until the Treaty of Westminster was signed in April 1654, its last major action was the Battle of Scheveningen in July 1653.

[1] In the Battle of Cadiz (9 September 1656) he commanded the 52-gun Tredagh in Captain Richard Stayner's squadron and captured a merchantman intact with its valuable cargo.

The incident caused a scandal and a parliamentary inquiry was held in which Harman was absolved of all blame, which was laid on Brouncker.

Sir John drew his sword and threatened to kill any other men who tried to leave the ship or who failed to fight the fire.

The remaining crew managed to quench the fire, but the burnt rigging let one of the top-sail yards fall and it broke Harman's leg.

Harman managed to make enough repairs to put to sea again the next day, hoping to resume the fight despite his broken leg.

[6] With the Henry as his flagship Harman played a conspicuous part in the St. James's Day Battle on 4–5 August 1666 off the North Foreland of the coast of Kent.

He failed to recapture the island, and was holding a council of war when news arrived that 23–24 French warships and 3 fire ships were lying at Martinique.

Harman directed his fleet to Martinique, where he found the French ships lying close to the shore under the protection of the batteries.

La Barre and Clodoré were arguing when Harman's fleet arrived and in the Battle of Martinique bombarded the French ships off Saint-Pierre.

The next morning he entered the river on the Bonaventure accompanied by the Assurance and Norwich, the Portsmouth and Roe ketches under lieutenant-general Henry Willoughby and a sloop.

[10] In this expedition Allin was sent to punish the Barbary corsairs for violating the treaty between England and Algiers and plundering English merchantmen.