So Joo-yeon started out as a model before transitioning into acting in the 2018 horror film The Whispering. That same year, she starred in the web drama Not Alright, But It’s Alright. In 2019, she played main characters in KBS2’s I Hate Going to Work and tvN D’s Wild Guys. In 2020, she appeared in the second season of the hit SBS series Romantic Doctor Teacher Kim, which won her Best New Actress at the SBS Drama Awards. She later joined the main cast of KakaoTV’s original drama series Lovestruck in the City. Also in 2020, she portrayed the female lead role in the Korean adaptation of the popular Chinese drama A Love So Beautiful, opposite Kim Yo-han.