HMS Inflexible was a 64-gun third rate ship of the line of the Royal Navy, launched on 7 March 1780 at Harwich.

Because Inflexible served in the navy's Egyptian campaign (8 March to 8 September 1801), her officers and crew qualified for the clasp "Egypt" to the Naval General Service Medal that the Admiralty authorized in 1850 to all surviving claimants.

[Note 1] In 1807 she was present at the Battle of Copenhagen, joining on 7 August off Helsingor (Captain Joshua Rowley Watson).

Inflexible became a storeship in 1793, and was eventually broken up in 1820.

This article about a ship of the line of the United Kingdom is a stub.