Sieun (시은) is a Korean singer under High Up Entertainment. She is a member of the Korean pop girl group STAYC.
- Stage Name: Sieun (시은)
- Birth Name: Park Sieun (박시은)
- Birthdate: August 1, 2001
- Birthplace: Seoul, South Korea
- Blood Type: A
- Height: 160cm
- Weight: 44kg
- Role Model: IU
- Seoul SinYongsan Elementary School (Transferred)
- SangMyung Elementary School (Graduated)
- SangMyung Middle School (Graduated)
- Goyang Arts High School (Dept. of Acting – Graduated)
- Chung-Ang University (Dept. of Performing Arts and Visual Creation, Theater Major – Leave of Absence)
- [2018.12.31] 2018 SBS Drama Awards: Best Young Actress - Still 17
- She is the daughter of first generation singer Park Namjung.
- She joined JYP Entertainment on January 18, 2017, and she left the company in 2020.
- She can speak English.
- She can play the piano.
- Her favorite artists are G-Dragon and Apink.