| Full Name | Lee Seo-yeon |
| Stage Name | Seoyeon |
| Native Name | 이서연 |
| Birthday | January 22, 2000 |
| Age | 25 years and 6 months old |
| Zodiac Sign | Aquarius |
| Birthplace | Mok-dong, Yangcheon-gu, Seoul, South Korea |
| Height | 5’2″ (158 cm) |
| Weight | 92.6 lbs (42 kg) |
| Blood Type | A |
| MBTI | ISTJ |
| Education | School of Performing Arts Seoul |
| Languages | Korean |
| Group | fromis_9 (2017 – January 26, 2025) |
| Social Media | Instagram: [@im_theyeon] |