Joint Advisory Commission, Korea

The Joint Advisory Commission, Korea (JACK; ) was a U.S. covert operations unit that participated in the Korean War.

Operating under the direction of the Central Intelligence Agency, JACK was responsible for inserting and extracting U.S.-trained Korean agents into North Korea, conducting covert maritime raids along the North Korean coast, and providing escape and evasion support for downed Air Force pilots.

Yong-do Group based in Yeongdo District, Busan was the main guerrilla unit.