Jae Weong Seo (; Hanja: 徐在應; ; born May 24, 1977), usually referred to as simply Jae Seo and pronounced "Jay So", is a retired South Korean professional baseball pitcher. He played in Major League Baseball (MLB) for the New York Mets, Los Angeles Dodgers, and Tampa Bay Devil Rays. Seo subsequently returned to South Korea to join the KBO League's Kia Tigers.

Career

Seo attended Gwangju Jeil High School (graduating in 1996), and Inha University in Incheon, South Korea, where he led his team to the Korean collegiate championship in 1997.

In , Seo was signed as a free agent by the New York Mets. After an excellent first year of professional play, Seo underwent reconstructive surgery on his elbow in .