---
title: "Youngseo (영서) of ALLDAY PROJECT"
url: https://coolkpop.com/idols/allday-project-youngseo
as_of: 2026-10-30
---

# Youngseo (영서) of ALLDAY PROJECT

Placed 2nd overall on R U Next? before signing with THEBLACKLABEL to anchor ALLDAY PROJECT’s vocal hooks.

| Field | Value |
| --- | --- |
| Group | [ALLDAY PROJECT](https://coolkpop.com/artists/allday-project) |
| Agency | THEBLACKLABEL |
| Birth name | Lee Young-seo |
| Born | 2005-11-13 |
| Nationality | South Korean |
| Positions | Main Vocalist, Maknae |
| Height | — |
| Activity status | active |