The Racer-class sloop also known as the Cordelia class of swift cruisers[1] was an 11-gun wooden screw sloop class of five ships built for the Royal Navy between 1855 and 1860.

Built of a traditional wooden construction, the Racer class were a lengthened version of the Swallow-class sloop, which in turn had been intended as "type of screw vessel below the Cruizer".

The extra length gave greater speed, and combined with a considerable increase in power, this gave a speed of about 10 knots (19 km/h), rather more than the 7 knots (13 km/h) of the previous class.

[3] Propulsion was provided by a two-cylinder horizontal single-expansion steam engine developing 461 indicated horsepower (344 kW) and driving a single screw.

At maximum power under steam, top speed was about 10 knots (19 km/h).