HMS Royalist was a Bellona-class (improved Dido-class) light cruiser of the Royal Navy (RN) during the Second World War.

After commissioning in 1943, Royalist was modified with extra facilities and crew for operating as a flagship for aircraft carrier operations. Initially, it operated in the North Sea before transferring to the Mediterranean for the invasion of southern France. Royalist remained in the Mediterranean for actions against German forces in the Aegean to the end of 1944. Then it moved to the Far East in February 1945 where it served until the end of the war.

The Royalist was then put into reserve until 1953 when the RN decided to proceed with plans to refit the ship for a new intended operational role as a fast radar picket. The cost of reconstruction and reactivation of the ship led the RN to transfer the vessel to the Royal New Zealand Navy (RNZN) in 1956 as a replacement for its sister ship HMS Bellona, which had been in New Zealand service since 1947. In return, New Zealand covered the reconstruction costs of the Royalist. After ten years of service with the RNZN, which included involvement in the Suez Crisis in 1956 and the Indonesia–Malaysia confrontation from 1963 to 1965, the ship returned to the United Kingdom where it was scrapped.