The Hermes class were a series of four 20-gun ships, launched between 1811 and 1816. Two pairs of ships were produced, to slightly different designs – the first two had 20 guns and were unrated flush-decked ship-sloops, whilst the latter two were converted to 26-gun sixth-rates. The design was based on the ex-French 20-gun corvette Bonne Citoyenne, which the British had captured in 1796. The Cyrus class was based on the design of the Myrmidon of the Hermes class.