Henry Appleton (fl. 1650–1654) was an English captain in the navy and commodore.
He was a townsman and presumably a native of Hull; but his name does not appear in any list of naval officers during the civil war or until 26 September 1650, when an order was sent by the parliament to the council of state to appoint him `as commander of the ship now to be built at Woolwich, or any other ship that they think fit.´ This is the earliest mention of him as yet known. That his appointment was irregular and gave offence to his subordinates, officers of some experience at sea, and that he had neither the knowledge nor the ability to enforce obedience to his orders, appears throughout his whole correspondence, which gives an account of his sailing in the Leopard of 50 guns, of his arrival at Smyrna with the convoy, of his sailing thence in April 1651, and of his successive arrivals at Zante, Messina, Naples, and Genoa. In November 1651 he went to Leghorn, and immediately off that port captured, or permitted the ships with him to capture, a French vessel; thus, at the outset, giving offence to the Grand Duke of Tuscany. After staying a month at Leghorn he left for Naples, and with the Levant trade sailed again to Smyrna, returning to Leghorn in the end of June 1652.
The war with the Dutch Republic had just broken out, and a squadron of fourteen Dutch ships of war rendered it impossible for the English to move out. The force that Appleton had with him was not more than half that of the Dutch, and during the rest of the summer he attempted nothing beyond despatching the Constant Warwick to reinforce Commodore Richard Badiley, who was expected shortly on the coast of Italy. On 27 August 1652,. the Dutch learned that Badiley was off the island of Elba; and slipping out with their squadron, now of ten ships, they brought him to action, when, after a fight which lasted through that day and into the next, they succeeded in capturing the Phoenix. Appleton made no attempt to help Badiley, pleading afterwards ‘that the Lord had at that time visited him with a violent sickness;’ to which Badiley answered that no one else knew of it, and that even if he was sick he ought still to have sent his ships.