Kim Joo-hun began his acting career on stage before making his big screen debut with a minor role in the 2013 drama film Way Back Home. In 2016, he landed his first television acting gig in the OCN crime comedy Police Unit 38. In 2020, he became part of the main cast of the hit SBS series Romantic Doctor Teacher Kim 2, which won him Best Supporting Actor at the SBS Drama Awards. That same year, he played memorable characters in the high-rating tvN dramas It’s Okay to Not Be Okay and Start-Up and the KBS2 series Do Do Sol Sol La La Sol. In 2021, he acted alongside Song Hye-gyo and Jang Ki-yong in the SBS romance drama Now, We Are Breaking Up, which earned him an Excellence Award at the SBS Drama Awards.

Kim Joo-hun attended the Seoul Institute of the Arts.