Jeong Yun-o (Hangul: 정윤오) (born Jeong Jae-hyun; Hangul: 정재현) referred to as Jaehyun (Hangul: 재현) or Jay (in English) is a South Korean singer-songwriter, actor and rapper born in Seoul on February 14, 1997. He is one of the main vocalists and lead dancers of NCT U and a main vocalist, lead dancer, and sub rapper of NCT 127.