USS Block Island (CVE-21/AVG-21/ACV-21) was a Bogue-class escort carrier for the United States Navy during World War II. She was the first of two escort carriers named after Block Island Sound off Rhode Island. Block Island was launched on 6 June 1942 by Seattle-Tacoma Shipbuilding Corporation of Seattle, Washington, under a Maritime Commission contract; sponsored by Mrs. H. B. Hutchinson, wife of Commander Hutchinson; transferred to the United States Navy on 1 May 1942; and commissioned on 8 March 1943, Captain Logan C. Ramsey in command. Originally classified AVG-21, she became ACV-21 on 20 August 1942, and CVE-21 on 15 July 1943.