The singer of the hit song 'Splish Splash' is Bobby Darin, a five-letter name. Darin was an American singer, songwriter, multi-instrumentalist, and actor who performed in a wide variety of music genres, including pop, rock, jazz, folk, and country. He had several hits throughout his career, including 'Mack the Knife' and 'Beyond the Sea'. His 1958 single 'Splish Splash' was his first major hit and reached number three on the Billboard Hot 100 chart.