Park Jin-ju made her acting debut in the 2011 blockbuster comedy-drama film Sunny. She has since appeared in numerous TV series and movies, mostly playing supporting characters. In 2014 and 2015, she joined the SBS dramas Angel Eyes, Modern Farmer, and Girl Who Sees Smells. In 2016, she became part of SBS’s Jealousy Incarnate and the Dramax series 1% of Anything. In 2017, she was cast in the SBS fantasy romance drama Reunited Worlds, which won her Best Supporting Actress at the SBS Drama Awards. In 2019, she portrayed Park Min-young’s best friend in tvN’s Her Private Life. In 2020, she acted alongside Kim Soo-hyun and Seo Ye-ji in the hit tvN drama It’s Okay to Not Be Okay. In 2021, she played another best friend role in the SBS series Our Beloved Summer, which earned her an Excellence Award nomination at the SBS Drama Awards.

Park Jin-ju studied at the Seoul Institute of the Arts.