Ok Ja-yeon made her acting debut in the 2012 theater play Guest. This was followed by appearances in more stage productions such as King Claudius and Hamlet Avatar in 2014. In 2016, she portrayed the female lead in the play Blackbird. That same year, she landed a small role in the period action-thriller film The Age of Shadows. In 2017, she became part of MBC’s Two Cops and OCN’s Bad Guys: City of Evil. In 2018, she joined the award-winning psychological drama film Burning. In 2019, she played supporting roles in the movies The Beast and Ashfall. In 2020, she was cast in OCN’s The Uncanny Counter. In 2021, she bagged her first main role on television in the hit tvN series Mine. Her performance in the series earned her a Best Supporting Actress nomination at the 58th Baeksang Arts Awards.

Ok Ja-yeon attended the Seoul National University’s Department of Aesthetics.