Katsuhiko Nakajima (中嶋 勝彦, Nakajima Katsuhiko?, born March 11, 1988) is a Japanese professional wrestler, represented as a freelancer by his mentor Kensuke Sasaki's Diamond Ring dojo and agency. He along with Sasaki and other Kensuke Office graduates currently most frequently wrestle in Pro Wrestling Noah as well as sporadic self-produced independent shows. Prior to that Nakajima wrestled for All Japan Pro Wrestling, where he is a former AJPW World Junior Heavyweight Champion.
Having made his professional debut aged 15, Nakajima has already made a significant impact on puroresu, earning the nickname "Supernova" and facing Hall of Famers such as Kenta Kobashi, Satoru Sayama, Jushin Liger, and Tatsumi Fujinami. He has competed in several notable Japanese promotions, including New Japan Pro Wrestling, All Japan Pro Wrestling, Inoki Genome Federation, Pro Wrestling Zero1, Michinoku Pro, Dragon Gate, and currently, Noah.
He has set several age records over his short career, including being the youngest wrestler to compete in AJPW's Champion's Carnival tournament and the youngest to hold the AJPW Junior Heavyweight Championship. He won the Tokyo Sports Grand Prix "Rookie of the Year" award in 2004 and the Fighting Spirit award in 2005.