Several ships of the Royal Navy have carried the name HMS Orestes, after the mythical son of Agamemnon, who avenged his father's murder:
was a Dutch-built brig-sloop. She was captured from the Dutch in 1781, taken into Royal Navy service, and disappeared in the Indian Ocean in 1799. was a ship sloop of 14 guns, purchased in 1803; her crew burnt her in 1805 to prevent the enemy capturing her. was a of 16 guns, launched in 1805 and sold in 1817. was a sloop, launched on 31 May 1824 and converted into a coal depot in 1852. was a , launched on 18 August 1860 and scrapped in 1866. , an , launched in 1916 and sold for scrap in 1921. was an , sunk as a target in Seacat missile trials.