HMS Caesar, also Cæsar, was an 80-gun third rate ship of the line of the Royal Navy, launched on 16 November 1793 at Plymouth.

She was designed by Sir Edward Hunt, and was the only ship built to her draught.

[2] She was involved in the Battle of Algeciras Bay in 1801, during which her Master, William Grave, was killed[3] On 30 April 1802, under command of Sir James Saumarez, 1st Baron de Saumarez, she made contact with USS Constellation near Gibraltar.

[4] The Battle of Cape Ortegal was the final action of the Trafalgar Campaign, and was fought between a squadron of the Royal Navy and a remnant of the fleet that had been destroyed several weeks earlier at the Battle of Trafalgar.

It took place on 4 November 1805 off Cape Ortegal, in north-west Spain and saw a squadron under Captain Sir Richard Strachan in Caesar defeat and capture a French squadron under Rear-Admiral Pierre Dumanoir le Pelley.