Park Si-eun is a South Korean singer and actress. After debuting as a child actress in 2014, she starred in several television series and films, winning the award for Best Young Actress at the 2018 SBS Drama Awards for her role as young Woo Seo-ri in Still 17. She was both an actor and idol trainee in JYP Entertainment, but left the company in 2019 after JYP Actors became defunct. After signing with High Up Entertainment in December 2019, she debuted as a member of the girl group STAYC in November 2020.

Still 17 is a 2018 South Korean television series starring Shin Hye-sun, Yang Se-jong and Ahn Hyo-seop. It aired on SBS TV from July 23 to September 18, 2018, every Monday and Tuesday at 22:00 (KST) for 32 episodes.