JJK may refer to:
Jujutsu Kaisen, a Japanese manga series by Gege Akutami Jujutsu Kaisen (TV series) JJK Jyväskylä, a Finnish football team from the city of Jyväskylä John "Julius" Knight, American musician Jesper Kyd, Danish video game composer Jacqueline "Jackie" Joyner-Kersee, American former heptathlon athlete Jeon Jungkook, the lead singer of K-pop group BTS