RMMV Capetown Castle was a passenger liner and mail ship for the British Union-Castle Line. The ship was built by Harland & Wolff at Belfast and launched on 23 September 1937. In 1940, during World War II she was requisitioned for conversion into a troop ship. In 1943 she took part in Operation Bolero, the build-up of troops in preparation for D-Day, and was eventually returned to her owners in 1946, having sailed 484,000 miles and carried over 164,000 troops. The ship was refurbished at Belfast and returned to commercial service on 9 January 1947.