HMS Conqueror was a 120-gun Caledonia-classfirst rate launched in 1833 as HMS Waterloo. She was rearmed to 89 guns and converted to steam propulsion in 1859, and was renamed Conqueror in 1862. In 1877 she was renamed Warspite and served as a training ship at for the Marine Society. She was burnt in 1918.
HMS Conqueror (1939) was to have been a Lion-class battleship. She was laid down in 1939 but construction was suspended later that year, and she was cancelled entirely in 1945.
HMS Conqueror (S48) was a Churchill-class nuclear submarine launched in 1969. The only nuclear submarine ever to sink an enemy warship, she was paid off and laid up in 1990.