Five ships and one submarine of the Royal Navy have been named HMS Agamemnon, after the legendary Greek king Agamemnon. was a 64-gun third-rate launched in 1781. She took part in the Battle of Trafalgar in 1805 and was wrecked in 1809. was a 91-gun screw-propelled second-rate launched in 1852 and sold in 1870. was an battleship launched in 1879 and broken up in 1903. was a battleship launched in 1906, used as a target ship from 1920 and sold in 1927. was a civilian cargo ship requisitioned as an auxiliary minelayer for the Northern Barrage in 1940 and returned in 1946. is an nuclear submarine commissioned in 2025.
Battle honours Ushant 1781 The Saints 1782 Genoa 1795 Copenhagen 1801 Trafalgar 1805 San Domingo 1806 Crimea 1854–55 Dardanelles 1915–16
See also , an early long-distance merchant steamship with a fuel efficient compound engine.