Kim Woo Seok made his debut twice as a member of an idol group. He first debuted as a vocalist, visual, and face of the group of UP10TION under TOP Media back in September 2015 with an extended play titled "Top Secret." He rose to fame when he competed in Mnet's boy group survival show "Produce X 101," together with his bandmate Lee Jin Hyuk in 2019.
During the program, Kim Woo Seok won the hearts of the fans and viewers through his mesmerizing performances. In particular, the male idol made a huge impression after his killer performance as the center of the team that performed EXO's "Love Shot." Following that, he ranked No.1 on the Non-Drama Popularity Ranking in May 2019 that was released by Good Date Corporation.