HMS Boyne was a 70-gun third rate ship of the line of the Royal Navy, built at Plymouth Dockyard to the draught specified in the 1745 Establishment as amended in 1754, and launched on 31 May 1766. She was first commissioned for the Falkland Crisis of 1770 after which, in 1774, she sailed for North America. From March 1776, she served in the English Channel then, in May 1778, she was sent to the West Indies where she took part in the battles of St Lucia, Grenada and Martinique. In November 1780, Boyne returned home, where she was fitted for ordinary at Plymouth. In May 1783, she was broken up.

The Battle of St. Lucia or the Battle of the Cul de Sac was a naval battle fought off the island of St. Lucia in the West Indies during the American Revolutionary War on 15 December 1778, between the British Royal Navy and the French Navy.