Originally ordered in April 1847 as a "Screw Schooner", she was suspended in August 1847 and re-ordered on 1 November 1850 to the same design as HMS Cruizer. The wooden sloops of the Cruizer class were designed under the direction of Lord John Hay, and after his "Committee of Reference" was disbanded, their construction was supervised by the new Surveyor of the Navy, Sir Baldwin Walker. Hornet was laid down at the Royal Dockyard, Deptford in June 1851. Her two-cylinder horizontal single-expansion steam engine, which was supplied by James Watt & Company at a cost of £5,450, generated an indicated horsepower of ; driving a single screw, this gave a maximum speed of . The class was given a barque-rig sail plan.