YOUNGSEO
ALLDAY PROJECT · Vocalist · Performer · Youngest member
Photo : THEBLACKLABEL
Profile
YOUNGSEO, Lee Young-seo, is a singer and performer in the Korean co-ed group ALLDAY PROJECT. She was born November 13, 2005, and is the youngest member of the five-person lineup unveiled by THEBLACKLABEL.
Before joining ALLDAY PROJECT, Youngseo competed on the televised survival program R U Next?. She had previously been announced as part of the planned ILLIT lineup, but departed before that group’s debut. The pre-debut context explains her prior public visibility, not an additional group recording debut.
YOUNGSEO made her official music debut with ALLDAY PROJECT on June 23, 2025, through FAMOUS and WICKED. Her vocals and stage presence also appear on ONE MORE TIME and LOOK AT ME from the first EP, then TALK, DO IT LIKE THIS and CRASH from the September 2026 second EP.
At the October 2026 editorial cutoff, no independently marketed solo album or single by YOUNGSEO was established. Her personal Instagram is distinguished from the group’s official channels.
Career Milestones & Individual Activities
September 28, 2026 · CRASH
Participated in the group’s second EP and title-track music video.
December 8, 2025 · ALLDAY PROJECT EP
Sang on group tracks including LOOK AT ME.
June 23, 2025 · Group debut
Debuted with ALLDAY PROJECT under THEBLACKLABEL.
2023 · R U Next?
Appeared on the pre-debut survival program that formed another group; did not debut with ILLIT.
Personal SNS
Member News & Further Reading
Latest KWaveScope news will appear here.
Fact check: October 26, 2026. Group and subunit songs are not counted as an independent solo debut. No fan-managed accounts included.