Jung Sung-il (October 21, 1969) is a South Korean retired competitive figure skater. He is the 1991 Winter Universiade silver medalist. He placed as high as sixth at the World Junior Championships (1988) and 14th at the World Championships (1991). A three-time Olympian, he placed 22nd at the 1988 Winter Olympics, 21st at the 1992 Winter Olympics, and 17th at the 1994 Winter Olympics.