British admiral and, intermittently, Conservative member of Parliament who frequently and outspokenly criticized Admiralty policy.

Second son of the 4th Marquess of Waterford, Beresford distinguished himself as commander of the gunboat Condor at Alexandria (1882) and as commander of the Nile naval brigade at Abu Klea (1885). Appointed 4th sea lord (1886), he resigned (1888) over disagreement with Admiralty policy. Promoted to flag rank (1897) and admiral (1906), he commanded the Channel Squadron (1903–05) and Mediterranean Fleet (1905–07). While commanding the Channel Fleet (1907–09), he became opposed to the fleet reorganization policies of the 1st sea lord, Sir John Fisher, and was ordered to haul down his flag. He then attacked Admiralty policy in a letter to the prime minister, H.H. Asquith. Some of his recommendations, notably the introduction of a naval general staff, were implemented later.

Elected several times as a member of the House of Commons between 1874 and 1910, Beresford consistently sought public support for the development of sea power. He went to the House of Lords as Baron Beresford (1916). He published his views of naval problems in The Betrayal (1912) and Memoirs (1914).