Kim Sung-chul made his acting debut in the 2014 musical Puberty. In 2017, he was named Best New Actor at the Korea Musical Awards for his work in Sweeney Todd. That same year, he landed his first small screen role as an inmate in the hit tvN series Smart Prison Living. In 2019, he appeared in the action-war film The Battle of Jangsari along with Kim Myung-min, Megan Fox, and Min-ho. The movie earned him the Best New Actor trophy at the 27th Korea Culture and Entertainment Awards. In 2020, he acted alongside Park Eun-bin and Kim Min-jae in the SBS romance drama Do You Like Brahms, which scored him a Best New Actor nomination at the SBS Drama Awards. In 2021, he was nominated for an Excellence Award at the SBS Drama Awards for his performance in the romantic comedy Our Beloved Summer.

Kim Sung-chul majored in theater arts at the Korea National University of Arts. He is close friends with actor Lee Sang-yi, who was his college classmate.