HMS Blenheim was a 90-gun second-rate ship of the line of the Royal Navy, built by Israel Pownoll and launched on 5 July 1761 at Woolwich. In 1797 she participated in the Battle of Cape St Vincent. In 1801 Blenheim was razeed to a third rate. She disappeared off Madagascar with all hands in February 1807.

The Battle of Cape St. Vincent was one of the opening battles of the Anglo-Spanish War (1796–1808), as part of the French Revolutionary Wars, where a British fleet under Admiral Sir John Jervis defeated a greatly superior Spanish fleet under Admiral Don José de Córdoba y Ramos near Cape St. Vincent, Portugal.