Kim Dong-joon debuted as a member of the South Korean boy group ZE:A in 2010 with the single album Nativity. Also known as the Children of Empire, the group’s long list of discography includes three studio albums, four extended plays, and 14 singles. ZE:A has not officially disbanded despite some of its members parting ways with the group’s management agency in 2017.

Kim Dong-joon made his acting debut in 2010 with a cameo appearance in the SBS series Prosecutor Princess. In 2016, he became part of KBS2’s Neighborhood Lawyer Jo Deul-ho and then starred in the KBS1 daily series Still Loving You. His performance in the latter earned him an Excellence Award nomination at the KBS Drama Awards. In 2017, he joined the main cast of OCN’s Black. In 2019, he acted alongside Lee Jung-jae and Shin Mina in the JTBC political drama Chief of Staff. In 2020, he got stuck in a love triangle with Ong Sung-woo and Shin Ye-eun in JTBC’s More Than Friends.

Kim Dong-joon enlisted as an active-duty soldier for his conscription in July 2021.