Hongjoong (born: 김홍중 (Kim Hong-Joong)) is a South Korean rapper, vocalist, songwriter, and composer. He is the leader of the K-Pop group ATEEZ and is signed under the label KQ Entertainment.

Hongjoong was a contestant on the show MIXNINE from late 2017 to early 2018. He was eliminated in episode 10. He made his debut in October 2018 as a member of ATEEZ. As one of the primary songwriters for the group, Hongjoong has 149 songs credited under his name on the Korea Music Copyright Association.

His first mainstream solo release came in 2024 when he collaborated with South Korean singer CHUNG HA on her song “EENIE MEENIE.” In 2025, Hongjoong collaborated with Palestinian-American rapper and producer Odetari on his song “SMB.”