Jin Ki-joo placed third in SBS’ Supermodel Contest in 2014, paving the way for her acting debut in the 2015 tvN romantic comedy series Second 20s. The year 2018 was an eventful year for Jin Ki-joo’s acting career. She was cast in the drama film Little Forest, which won her Best New Actress at the 24th Chunsa Film Art Awards. She also got Best New Actress nominations from major award-giving bodies such as the Baeksang Arts Awards and the Grand Bell Awards for her performance in the film. She also starred as the protagonist’s main rival in the 2018 JTBC melodrama mystery series Misty, in which she was nominated for Best New Actress at the 6th APAN Star Awards. It was also in 2018 when Jin Ki-joo landed her first leading role in the MBC melodrama thriller Come Here and Hug Me. In 2020, she headlined the KBS2 family weekend drama Homemade Love Story, which earned her an Excellence Award at the KBS Drama Awards.

Prior to her foray into the entertainment industry, Jin Ki-joo worked at Samsung SDS for three years and as a reporter for SBS regional affiliate G1.