Vocal: "composer" Benny Davis, who was also credited for Margie, just for the willingness to record it. Real author Harry Akst also wrote Am I Blue.
Little Richard [n°2 UK; very impressed with Fats Domino's success with that other pre war oldie Blueberry Hill (see there)]
Brian Hyland [B-side of Itsy Bitsy Teeny Weeny Yellow Polkadot Bikini]
Lucky Blondo [French version]
Julie Andrews [in film Thoroughly Modern Millie]