HMS Unicorn was an aircraft repair ship and light aircraft carrier built for the Royal Navy in the late 1930s. She was completed during World War II and provided air cover over the amphibious landing at Salerno, Italy, in September 1943. The ship was transferred to the Eastern Fleet in the Indian Ocean at the end of the year. Unicorn supported the aircraft carriers of the fleet on their operations until the British Pacific Fleet (BPF) was formed in November 1944. She was transferred to Australia in early 1945 to support the BPF's operations during Operation Iceberg, the Allied invasion of Okinawa in May. To shorten the time required to replenish the BPF's carriers, the ship was based in the Admiralty Islands and in the Philippine Islands until the Japanese surrender in August. Unicorn was decommissioned and placed in reserve when she returned to the UK in January 1946.

A light aircraft carrier, or light fleet carrier, is an aircraft carrier smaller than the standard carriers of a navy. The precise definition of the type varies by country; light carriers typically have a complement of aircraft only one-half to two-thirds the size of a full-sized fleet carrier. A light carrier was similar in concept to an escort carrier in most respects, however light carriers were intended for higher speeds to be deployed alongside fleet carriers, while escort carriers usually defended equally slow convoys and provided air support during amphibious operations.