Pre–debut Moon met a
talent agent during a competition, who would later call him for an audition. He danced to an
Usher song and received his notice of acceptance on his way home. He became a trainee under
TS Entertainment in August during his first year in high school.
2012–2019: B.A.P Moon was revealed as a member of
idol sextet
B.A.P on January 17, 2012, where he served as a sub-vocalist and main dancer. The group debuted nine days later with their single album
Warrior. In November 2014, B.A.P filed a lawsuit against its agency. The members sought to nullify its contract with the company citing "unfair conditions and profit distribution". In August of the following year, the two parties ultimately settled and B.A.P resumed its activities under TS Entertainment. Moon performed his first solo song entitled "Try My Luck" during B.A.P's 2017 World Tour 'Party Baby!' in March. A
PBR&B track, it was released as part of a project album with fellow member
Daehyun on June 8. In August and December 2018, Yongguk and
Zelo left the group and record label following the expiration of their contracts, respectively. Moon and the remaining three members left the agency in February 2019, leading the dissolution of B.A.P. Following B.A.P's disbandment, Moon took a six-month break from music.
2019–present: New agency, and solo debut Moon was cast for an encore show of the theater production
The Lost Village; the performance took place on April 27, 2019. Set in
Jeju Island amid the historical events of 1979, he played the young version of bar owner Donghyuk. Moon was a contestant on
Maeil Broadcasting Network's survival reality show
Signhere (2019), where participants auditioned to join
Jay Park's record label
AOMG. He passed the first round, but was eliminated in the second after his collaborative performance with MBA. In November, Moon signed an exclusive contract with The Groove Company. On May 7, 2020, he released his debut
single album Headache and its
funk-
pop title track. On July 8, 2021, he released his first extended play
Us. On May 31, Moon announced that RE:MEET fan meetings will be held in Japan on July 30 and 31, 2022. On February 15, 2023, he was revealed as a contestant on
JTBC's
Peak Time and took part in TEAM 24:00. The group placed 3rd in the final round. In 2023, Moon Jongup to Hold Meet & Greet at The Shops at Skyview’s K-Pop Day in New York. On October 5, a teaser was released for Moon's second mini album,
Some. The album was later released on October 30. On October 31, 2024, he released his third mini album,
Peter. On May 19, 2025, Jongup announced that he would be enlisting on the same day. ==Musical style==