NCT 127 is a South Korean boygroup formed by S.M. Entertainment in July 2016, a second sub-unit from the main group NCT (엔시티) . The group is composed of nine members: Jungwoo, Haechan, Yuta, Taeyong, Jaehyun, Mark, Johnny, Doyoung and Taeil.

The group made their stage debut on July 7, 2016 on M! Countdown, performing “소방차 (Fire Truck)” and “Once Again (여름 방학)”. Their debut extended play titled NCT #127 was released digitally on July 10 and physically on July 11.