Kim Dong-hee made his acting debut in the 2018 web series A-Teen. He next appeared in the hit JTBC drama SKY Castle, which won four trophies at the 55th Baeksang Arts Awards. In 2020, he played a supporting character in the popular JTBC series Itaewon Class, which was followed by a leading role in the Netflix teen crime drama Extracurricular.

Kim Dong-hee graduated from Anyang Arts High School and then enrolled at Gachon University’s Department of Acting Arts. In 2021, the actor got embroiled in a school bullying controversy. He later issued an apology after admitting that he bullied a classmate in elementary school.