Park Si Eun (박시은) is a South Korean singer and actress currently under Highup Entertainment. She is a member of the girl group STAYC. Her father, Park Nam Jung, is a famous singer from the 80's.
Sieun originally made her debut as a child actress in 2014 through the children's television series Pluto Secret Society.
She debuted as a member of STAYC on November 12, 2020 with their first single album "Star To A Young Culture".