Sylvester Sim (Chinese: 沈祥龙; pinyin: Shěn Xiánglóng; born January 19, 1983) is a Singaporean singer. He was the first runner-up of the talent contest Singapore Idol. He is widely known as Sly to his fans. He used to be part of the popular J-rock band L'zefier.
A self-professed rocker and play-do, his boy-boy image resulted in him nearly getting eliminated from the contest. In fact, he beat out hot favorite Olinda Cho to get to the Finals of Singapore Idol season 1, and came out as the first runner up on December 1, 2004. The following month, a report that he was engaged to fellow contestant Maia Lee caused a minor scandal, but they have since cancelled their engagement, saying that they are concentrating on their careers.
The multi-talented Sim does well in his singing career in different languages like Chinese, English and even Japanese. Sim's much awaited first album, Take Flight, was released in April 2005. He also has a role in Shooting Star as a coffee-shop owner's son in Singapore. He terminated his contract with his management, Hype Records, in July 2006, citing personal reasons.