The USS St. Louis (CL-21) was a light cruiser of the United States Navy, commissioned in 1939. It was part of the Brooklyn-class cruisers, designed for speed and agility. The ship played a significant role during World War II, participating in various naval battles in the Pacific Theater. Throughout its service, the USS St. Louis was involved in key operations, including the Battle of Guadalcanal and the Battle of Leyte Gulf. The ship was known for its effective anti-aircraft capabilities and contributed to the protection of Allied forces. It was decommissioned in 1949 and later sold for scrap.