HMS Penelope was one of eight light cruisers built for the Royal Navy in the 1910s. She fought in the First World War, following the war, she was scrapped.
The Arethusa-class cruisers were intended to lead destroyer flotillas and defend the fleet against attacks by enemy destroyers. The ships were long overall, with a beam of and a deep draught of . Displacement was at normal and at full load. Penelope was powered by four Parsons steam turbines, each driving one propeller shaft, which produced a total of . The turbines used steam generated by eight Yarrow boilers which gave her a speed of about . She carried tons of fuel oil that gave a range of at .
The main armament of the Arethusa-class ships was two BL 6-inch (152 mm) Mk XII guns that were mounted on the centreline fore and aft of the superstructure and six QF 4-inch Mk V guns in waist mountings. They were also fitted with a single QF 3-pounder anti-aircraft gun and four torpedo tubes in two twin mounts.
She was launched on 25 August 1914 at Vickers Limited's shipyard. Unlike her sisters, she carried an extra 4-inch anti-aircraft gun in place of two 3-inch anti-aircraft guns. In August 1915, she was assigned to the 5th Light Cruiser Squadron of the Harwich Force, guarding the eastern approaches to the English Channel. On 25 April 1916 Penelope was damaged by a torpedo from the German submarine off the Norfolk coast. She was repaired and in March 1918 was reassigned to the 7th Light Cruiser Squadron of the Grand Fleet. She survived to the end of the First World War, and was sold for scrap in October 1924 to Stanlee, of Dover.