Moon Tae-il (Hangul: 문태일) referred to as Taeil (Hangul: 태일) is a South Korean singer, born in Jangan-dong, Dongdaemun-gu, Seoul on June 14, 1994. He was the main vocalist of NCT U and NCT 127 from 2016 to 2024. He left the group due to sexual offense charges.

His family consists of his mother, father, and younger sister. When he was young, he dreamed of becoming a zookeeper, but he listened to Stevie Wonder which made him want to become a singer.

In 2013, Taeil was discovered by SM Entertainment talent scouts at the Youth Singing Contest. At that time, Taeil had been admitted to the Music Department of Hanyang University. After a week of careful consideration, he decided to become a college student. Soon, he changed his mind and decided to become a singer.