Iku-Turso was a 500-tonne Vetehinen-class submarine that served in the Finnish Navy during the Second World War. It was launched in May 1931 and was named after a Finnish sea monster, Iku-Turso. It was built by the Crichton-Vulcan shipyard in Turku according to a project developed by NV Ingenieurskantoor voor Scheepsbouw , "IvS", and was scrapped in 1953.