Park Shi-eun began acting as a child, making her first TV appearance in the 2014 EBS children series Pluto Squad. That same year, she became part of MBC’s Pride and Prejudice, which was followed by a role in SBS’s Six Flying Dragons in 2015. In 2016, she played Jeon Do-yeon’s daughter in the tvN drama The Good Wife. She next portrayed the young counterparts of the female lead characters in the KBS2 sageuk Seven Day Queen and in the SBS rom-com Thirty But Seventeen. Her work in the latter won her Best Young Actress at the SBS Drama Awards. In 2019, she was cast in tvN’s The Crowned Clown and in the SBS miniseries Everything and Nothing.

Park Shi-eun debuted with the girl group STAYC in November 2020 with the single album Star to the Young Culture. The album’s lead single titled So Bad earned them a nomination for New Artist of the Year – Digital at the 10th Gaon Chart Music Awards.

Park Shi-eun’s mother is veteran singer Park Nam-jung.