The Speedy class was designed in 1781 by shipbuilder Thomas King. “Gun-brigs” like this were designed with a cutter style hull, part of the development of a new concept of the brig in naval warfare. This concept saw brigs as small, fast escort vessels, instead of the slower, larger brig and ship-sloops of war.

The two ships of this innovative class were named to epitomize this approach. HMS Speedy, and HMS Flirt were small, light craft, at a mere 207 Tons burden, and measured 78 feet on deck. Armed with light cannons (4 pounders) and many swivels for close in work.

Speedy was transferred to the Mediterranean after the outbreak of the French Revolutionary Wars. She had several notable commanders, winning fame for herself in various engagements -often against heavy odds.

Her first commander in the Mediterranean was Charles Cunningham, who served with distinction with several squadrons, assisting in the capture of several war prizes, such as the French frigates Modeste and Impérieuse. His successor, George Cockburn, is noted for his dogged devotion to duty. Speedy's next commander, George Eyre, had the misfortune to lose her to a superior French force on 9 June 1794.

She was soon retaken, and re-entered service under Hugh Downman, who captured several privateers between 1795 and 1799 and fought off an attack by the large French privateer Papillon on 3 February 1798. His successor, Jahleel Brenton, fought several actions against Spanish forces off Gibraltar.

Her last captain, the famed Lord Cochrane was underwhelmed with his new command, declaring Speedy was "little more than a burlesque of a vessel of war". His cabin had only 5 feet of headroom, thus when Cochrane wished to shave, he had to open a skylight and set his shaving equipment out on the quarterdeck. On another occasion he walked the quarterdeck with Speedy's entire broadside, seven pieces of four-pounder shot, in his pockets. In an attempt to increase the firepower of his new command he asked for and was given two 12-pounder long guns to use as bow and stern chasers, but the scantlings could not support them, and they had to be removed. He then requested his 4-pounders be upgraded to 6-pounders, but his gunports were not big enough. He had better luck with his mast, taking a spar from HMS Genereux that was considered too large for Speedy, but which Cochrane felt improved her speed.

Despite all this, Cochrane used her to capture many vessels and conduct shore raids against the enemy coast.  His most famous exploit in Speedy would come when he forced the surrender of the much larger Spanish frigate El Gamo, a xebec-frigate of 32 guns. A powerful French squadron captured her again in 1801 and Napoleon donated her to the Papal Navy the following year. She spent then finished her career with five years with the Papal Navy under the name San Paulo.