HMS Lancaster was a 64-gun third-rate ship of the line of the Royal Navy, launched on 29 January 1797 at Rotherhithe.

She was designed and built as the East Indiaman Pigot for the British East India Company, but the Navy purchased her on the stocks because of a shortage of naval vessels to prosecute the French Revolutionary Wars.

[3] In July 1800, Vice-Admiral Roger Curtis sent Lancaster, Adamant, Rattlesnake, and Euphrosyne to blockade Île de France and Bourbon.

[4][5] On 29 August 1806 Lancaster sailed from Simon's Bay as escort to a number of transports, including Pretty Lass, as part of the unsuccessful second British invasion of the River Plate.

[2] The Principal Officers and Commissioners of His Majesty's Navy offered her for sale on 30 May 1832 at Woolwich.