NCT U, a sub-unit of NCT, is a multi-membered South Korean boy group under SM Entertainment. This unit is characterized by its Contemporary R&B and Alternative sound and is less Pop-based than the other subunits NCT DREAM and NCT 127.

The group debuted in 2016 with the first lineup of five members; Taeyong, Mark, Jaehyun, Ten, and Doyoung. Kun and Taeil also performed as NCT U in 2016, promoting ballad “WITHOUT YOU,” which was also performed by Jaehyun, and Doyoung (for the Korean version).

However, NCT U is a rotational unit – and therefore the member-lineup is altered with each comeback depending on the song, choreography, and concept.