Lee Seo-yeon - Singer
Age: 25
Country: Korea, Republic of Occupations:
Singer
Lee Seo-yeon, also known by her stage name Y:SY, is a South Korean singer. She was born on January 22, 2000, in Seoul, South Korea.
She is best known as a former member of the girl group Fromis 9, where she was recognized for her versatility in singing, dancing, and rapping, and served as the main dancer and lead vocalist/rapper. She also has songwriting credits on some of the group's tracks.
Lee Seo-yeon departed from Fromis 9 after her contract with Pledis Entertainment expired at the end of 2024. In 2025, she signed an exclusive contract with H1ghr Music and officially began her solo career under the stage name Y:SY. Her solo debut digital single, "NAKED," was released in November 2025.
Before her debut with Fromis 9, she participated in the Mnet survival show Idol School in 2017, finishing in seventh place. She was also a former trainee at YG Entertainment for many years, beginning at age 10.