Chang Gyu-cheol
 Chang Gyu-Cheol (also Jang Gyu-Cheol Korean: 장 규철; born June 11 1992 in Gyeonggi-do) is a South Korean swimmer who specialized in butterfly events. In 2010 Chang edged out South Africa's Chad Le Clos by 0.18 of a second to claim a gold medal in the 100 m butterfly at the first ever Summer Youth Olympics in Singapore posting his personal best of 53.13.