HMS Cyclops was the lead ship of the Cyclops-class breastwork monitors built for the Royal Navy during the 1870s.

The engines produced a total of 1,528 indicated horsepower (1,139 kW) on 30 December 1871 during the ship's sea trials which gave her a maximum speed of 10.79 knots (19.98 km/h; 12.42 mph).

Cyclops carried 250 long tons (250 t) of coal,[3] enough to steam 3,000 nautical miles (5,600 km; 3,500 mi) at 10 knots (19 km/h; 12 mph).

The superstructure and conning tower was fully armoured, the reason it was called a breastwork, with 8–9 inches (203–229 mm) of wrought iron.

This refit also strengthened the breastwork and upper decks, added another watertight bulkhead as well as a false keel.

HMS Cyclops, like all of her sisters, was placed on the non-effective list in January 1902,[10][7] transferred to the E Division of the Dockyard Reserve at Sheerness in May 1902,[11] and sold on 7 July 1903[12] for £8,400.