| idol_id | 1426 |
| Selca owner | billlie_siyoon |
| Pop type | K-pop |
| Stage name (romanized) | Siyoon |
| Stage name (original) | 시윤 |
| Real name (romanized) | Kim Siyoon |
| Real name (original) | 김시윤 (金詩允) |
| Birth date | 2005-02-16 (age 21) ▲ ▼ |
| Chinese zodiac sign | 🐓 Rooster |
| Western zodiac sign | ♒ Aquarius |
| Hometown | Seoul |
| Height | 171.0cm (5'7") ▲ ▼ |
| Weight | 48.0kg (106lb) ▲ ▼ |
| Blood type | B |
| MBTI | INFP |
| Debut date | 2021-11-10 (4 years and 10 months ago) ▲ ▼ |
| Country of origin | 
Korea, Republic of |
| Name | Company | Fandom | Debut date | Disbandment date | Current member | |
|---|---|---|---|---|---|---|
|
Billlie (빌리) | Mystic Story | 2021-11-10 | Yes |