Joseph Koh Seng Leong (born 19 September 1983) is a Singaporean former sailor, who specialized in the Laser and 470 classes. He represented Singapore across two editions of the Summer Olympic Games (2000 and 2008), finishing outside the top twenty-five each in two separate boats, respectively. Outside Olympic career, Koh collected a total of two medals in a continental regatta, spanning the 2006 Asian Games in Doha and the 2007 Southeast Asian Games in Nakhon Ratchasima. Koh trained throughout his sporting career at SAF Yachting Club in Changi, under the tutelage of his personal coach Brett Beyer, a six-time Laser Apprentice Master world champion from Australia.