HMS James Watt was a 91-gun steam and sail-powered second rate ship of the line.

She was renamed on 18 November 1847 in honour of James Watt, the purported inventor of the steam engine.

[1] She was built at the Royal Dockyard, Pembroke Dock, launched on 23 April 1853 and commissioned at Plymouth in January 1854 by Captain George Elliot.

She served in the Baltic campaigns of 1854 and 1855, despite the poor performance of the ship, and the dissatisfaction of Vice-Admiral Charles Napier.

In August 1855 she was present at Cronstadt, the Russian Baltic naval base; along with HMS Imperieuse, Centaur and Bulldog The fleet was involved in a minor long-range Crimean War engagement near the Tolbukhin lighthouse [ru] with the port's batteries and gun-boats on 16 August 1855.