Lee Young Seo

Name: Lee Young Seo
Native name: 이영서
Also Known as: Lee Yeong Seo
Nationality: South Korean
Gender: Female
Born: November 13, 2005
Age: 19

Lee Young Seo is a South Korean singer, dancer, and member of ALLDAY PROJECT (올데이프로젝트). She graduated from Gaepo High School.

Before debuting, she spent nearly 5 years as a trainee at Source Music and was considered part of the girls who were set to debut in the agency's new group (known as NEWJEANS, later NJZ). Unfortunately, she was not chosen and decided to quit the company as a result.

In 2023, she entered the survival show "R U Next?" where she ended up in 2nd place. She qualified to join the resulting project group (later known as ILLIT), but in January 2024, she decided to terminate her contract with Be:Lift Lab.

She signed with THEBLACKLABEL (더블랙레이블) and was picked by rapper and producer Teddy to be part of the new co-ed group he was forming. She made her debut in June 2025 as ALLDAY PROJECT's vocalist and maknae with their first single album, "Famous".

(Source: kisskh) Edit Biography

Year	Title	#	Role	Rating
2025	Live Wire Korean TV Show, 2025, 12 eps (Ep. 6) (Guest)	12	(Ep. 6) Guest	0.0
2023	R U Next? Korean TV Show, 2023, 10 eps [Contestant] (Regular Member)	10	[Contestant] Regular Member	5.8
2018	Omniscient Interfering View Korean TV Show, 2018, 365 eps (Ep. 357) (Guest)	365	(Ep. 357) Guest	7.7
2005	Show! Music Core Korean TV Show, 2005, 1000 eps [Performer] (Guest)	1000	[Performer] Guest	8.0
2004	M Countdown Korean TV Show, 2004, 700 eps [Performer] (Guest)	700	[Performer] Guest	8.2
1991	Inkigayo Korean TV Show, 1991, 1240 eps [Performer] (Guest)	1240	[Performer] Guest	8.1