| Full Name | Yoon Se-eun |
| Stage Name | Seeun |
| Native Name | 윤세은 |
| Birthday | June 14, 2003 |
| Age | 22 years old |
| Zodiac Sign | Gemini |
| Birthplace | Bijeon-dong, Pyeongtaek, Gyeonggi-do, South Korea |
| Height | 5’6″ (167 cm) |
| Weight | 108 lbs (49 kg) |
| Blood Type | A |
| MBTI | INFP |
| Education | Kyungil High School |
| Languages | Korean, English, Japanese |
| Group | STAYC (2020-present) |
| Social Media | Instagram: [@i.m.princesseun] |