1THE9 (원더나인) was a nine-member project boy group signed under MBK Entertainment and managed by PocketDol Studio. They were formed through the competition reality show Under Nineteen and officially debuted on April 13, 2019 with the mini album XIX.
Pre-debut: Under Nineteen
Under Nineteen, which began airing on November 3, 2018, concluded on February 9, 2019 where the final 9 members were chosen during the live finale broadcast. It was also revealed the group would be called 1THE9.
2019: "Domino", Debut with XIX, Blah Blah
On April 5, the debut timeline started and the name of the album was revealed to be XIX with the title track being "Spotlight". A pre-debut title track, "Domino", which was written and produced by Under Nineteen's vocal trainer Crush, was released on April 7. The group then made their official debut on April 13 with the release of the mini album.
On April 17, they held their debut showcase through V Live, with their fandom and fandom color announced to be Wonderland and Lime Punch, respectively.
On October 17, 2019, 1THE9 released their second mini album Blah Blah.
2020: Turn Over and Good Bye 1THE9
On July 27, it was confirmed that the group would be disbanding on August 8. They were originally scheduled to disband on July 8 but due to their comeback being postponed due to the COVID-19 pandemic, it was extended by a month.
|6||Yoo Yong Ha (유용하)||Leader, Lead Rapper, Vocalist|
|3||Kim Tae Woo (김태우)||Vocalist, Rapper|
|6||Lee Seung Hwan (이승환)||Lead Dancer, Lead Vocalist|
|4||Shin Ye Chan (신예찬)||Main Vocalist, Lead Dancer|
|9||Kim Jun Seo (김준서)||Lead Vocalist, Lead Dancer, Rapper, Visual|
|1||Jeon Do Yum (전도염)||Main Dancer, Lead Rapper, Vocalist, Center|
|2||Jung Jin Sung (정진성)||Main Dancer, Lead Vocalist, Visual|
|5||Jeong Taek Hyeon (정택현)||Main Rapper, Vocalist, Face of the Group|
|7||Park Sung Won (박성원)||Main Rapper, Vocalist, Maknae|
- "Domino" (2019)
- Soompi: "Under 19" Reveals Final 9 Members Who Will Make Their Debut
- Soompi: "Under 19" Reveals Details About Debut Group And Contract
- Soompi: 1THE9’s Agency Confirms Report Regarding Group’s Disbandment Date
- Soompi: “Under 19” Reveals Final 9 Members Who Will Make Their Debut
- Soompi: "Under 19" Boy Group 1THE9 Announces Debut Date
- (KR) Naver: 원더나인, 멤버별 티저영상 릴레이 공개 예고 ‘데뷔 임박’
- (KR) V Live: 원더나인 1st MINI ALBUM 'XIX' 발매 기념 쇼케이스
- Wow TV: 원더나인, 16일 세 번째 미니앨범으로 컴백…강렬함 넘치는 이미지 공개
- Soompi: 1THE9 Announces Details For Last Mini Album “Good Bye 1THE9” Ahead Of Disbandment