Richard Kempenfelt (1718 - August 1782) was a British rear-admiral.

He was born at Westminster. His father, a Swede, is said to have been in the service of James II, and subsequently to have entered the British army. Richard Kempenfelt joined the navy, and saw service in the West Indies, taking part in the capture of Porto Bello during the War of Jenkins' Ear. In 1746 he returned to England, and from that date to 1780, when he was made rear-admiral, saw active service in the East Indies with Sir George Pocock and in various quarters of the world. In 1781 he won the Battle of Ushant, with a vastly inferior force, defeating the French fleet under De Guichen and capturing twenty ships.

In 1782 he hoisted his flag on HMS Royal George, which formed part of the fleet under Lord Howe. In August this fleet was ordered to proceed to the relief of Gibraltar, and underwent a refit at top speed at Portsmouth. A leak having been located below the waterline of the Royal George, the vessel was careened to allow of the defect being repaired. According to the version of the disaster favoured by the Admiralty, she was overturned by a breeze, and sank quickly at Spithead. The general opinion of the navy was that the shifting of her weights was more than the old and rotten timbers of the Royal George could stand. A large piece of her bottom fell out, and she went down at once. At least 800 people are thought to have gone down with the ship, for besides the crew there were a large number of tradesmen, women and children on board. Kempenfelt, who was in his cabin, perished with the rest. William Cowper's poem, the "Loss of the Royal George," commemorates this disaster. Kempenfelt had effected radical alterations and improvements in the signalling system then existing in the British navy. A painting of the loss of the Royal George is in the Royal United Service Institution, London.

See Charnock's Biog. Nav., vi, 246, and Ralfe's Naval Biographies, i, 215.