| Medal record | ||
|---|---|---|
Representing  South Korea
| ||
| Men's freestyle wrestling | ||
| Olympic Games | ||
 |
1996 Atlanta | 62 kg |
 |
2000 Sydney | 63 kg |
| World Championships | ||
|
1999 Ankara | 63 kg |
|
2001 Sofia | 69 kg |
| Asian Games | ||
 |
1998 Bangkok | 63 kg |
|
1994 Hiroshima | 62 kg |
Jang Jae-Sung (Hangul: 장재성, Hanja: 張在成; born March 15, 1975, in Incheon) is a retired South Korean freestyle wrestler.
Jang first garnered attention in the 1992 World Junior Wrestling Championships, held in Cali, Colombia, where he won the gold medal in the freestyle 63 kg class.
Jang won the silver medal in the freestyle 62 kg class at the 1996 Summer Olympics, where he defeated reigning world champion Elbrus Tedeyev of Ukraine 3–1 in the quarterfinals but lost to Tom Brands of United States 7–0 in the gold medal match.
Jang accumulated another Olympic medal at the 2000 Summer Olympics, where he lost to eventual gold medalist Mourad Oumakhanov of Russia in the semifinals but beat 1997 world champion Mohammad Talaei of Iran in the bronze medal match.
Jang participated in the 2008 Summer Olympics as an assistant coach of the South Korean national freestyle wrestling team. He currently serves as an assistant coach in the LH Wrestling Club.
