Sieun is the main vocalist of STAYC which is under High Up Entertainment. Her real name is Park Si Eun.
She is born on 1 August 2001 (Yes, under the Zodiac sign of Leo). She is 20 years old.
She stands at a height of 159 cm and weighs 44 kg. Her blood type is A.
Sieun is from Seoul, South Korea.