Dae-sung Koo

Koo Dae-sung
Pitcher
Born: (1969-08-02) August 2, 1969
Daejeon, South Korea
Batted: Left
Threw: Left
Professional debut
KBO: May 1, 1993, for the Binggrae Eagles
NPB: March 24, 2001, for the Orix BlueWave
MLB: April 4, 2005, for the New York Mets
Last appearance
KBO: September 3, 2010, for the Hanwha Eagles
NPB: September 27, 2004, for the Orix BlueWave
MLB: August 20, 2005, for the New York Mets
KBO statistics
Win–loss record67–71
Saves214
Earned run average2.85
Strikeouts1,221
NPB statistics
Win–loss record24–34
Saves10
Earned run average3.86
Strikeouts504
MLB statistics
Win–loss record0–0
Earned run average3.91
Strikeouts23
Stats at Baseball Reference 
Teams
Career highlights and awards
Medals
Olympic Games
Representing  South Korea
2000 Sydney Team
Dae-sung Koo
Hangul
구대성
Hanja
具臺晟
RRGu Daeseong
MRKu Taesŏng

Koo Dae-sung (Korean구대성; Hanja具臺晟; born August 2, 1969) is a Korean former professional baseball pitcher. A left-handed pitcher, Koo formerly played for the Hanwha Eagles in the KBO League, as well as the New York Mets of Major League Baseball and the Orix BlueWave of Nippon Professional Baseball. He announced his retirement from Korean baseball on August 15, 2010. He last played for Geelong-Korea in the Australian Baseball League. Since November 2025, Koo has served as the manager for the Shanghai Dragons of Chinese Professional Baseball.