Lee Dong-hyuck (Korean: 이동혁; born June 6, 2000), known professionally as Haechan (해찬), is a South Korean singer and dancer. Known for his distinctive vocal timbre, he rose to prominence as a member of the K-pop boy band NCT and its sub-units NCT 127 and NCT Dream.
Born in Seoul and raised between the city and Jeju, Haechan started training under SM Entertainment to become an idol in 2013. He began his career in 2014 as part of the label's official team of trainees, SM Rookies, appearing on television and touring both in South Korea and abroad. He made his debut in 2016 with NCT, going on to release over 30 albums and participate in nine concert tours over the span of a decade. The group achieved commercial success and became an influential K-pop act.
Developed with the songwriter and producer Deez, Haechan's debut studio album, the R&B and soul record Taste (2025), topped the Circle Album Chart and sold over 400,000 copies in South Korea.
2000–2013: Early life and musical beginnings
Lee Dong-hyuck was born on June 6, 2000, in Seoul, South Korea, as the oldest of four siblings. His parents, both musicians active in the local music scene, influenced his interest in music. Due to financial reasons, his mother moved to Jeju for work during his childhood, while Lee remained in Seoul with his father and grandparents. He grew particularly close to his grandmother, whom he credits with raising him until the age of six, when he joined his mother in Jeju. A band vocalist who enjoyed artists like Jaurim and Metallica, she influenced his musical taste by often bringing him to the noraebang and introducing him to singers like Michael Jackson. Lee said that he first listened to Jackson's single "Billie Jean" (1983) around the age of 10 and became "obsessed" with his music for a few years afterwards. He also admired several artists from SM Entertainment, particularly Taemin of Shinee, a group he first discovered through their debut single "Replay" (2008). Taemin later inspired him to audition for the label. In fifth grade, Lee passed the first round of an audition, but he struggled around the time of the second round due to the sudden death of his grandfather. He said that watching television music programs brought him comfort and happiness in that period.
Lee's mother initially opposed his ambition to become a singer but encouraged him to attend the SM Saturday Open Auditions in 2013. After passing multiple rounds by performing songs like "Hello" by Huh Gak, "Baby" by Justin Bieber, and "The Ugly Duckling" by Son Seung-yeon, he moved back to Seoul to begin training under the label, having drawn attention due to his high vocal range. At SM, teachers encouraged the trainees to emulate their favorite artists, which sparked Lee's renewed interest in Jackson. Aspiring to become a well-rounded artist like him, Lee began composing songs on the piano around the age of 15, seeking feedback from his piano teacher. He then persuaded his mother to buy him a MacBook laptop to explore music production with the software Logic Pro. Outside of SM, Lee also worked with the vocal coach and singer-songwriter Lim Han-byul, who named him among the students he was most proud to have taught. Meanwhile, he studied in the Applied Music department of the School of Performing Arts Seoul.
SM publicly introduced Lee as a member of its official training team, SM Rookies, on July 17, 2014, with a video of him and his fellow trainee Mark launching the group's website. The agency's first program of its kind, SM Rookies allowed trainees to gain experience and public exposure before their debut, often grouping them by gender and concept into distinct units. As part of the team, Lee appeared in the 2014 variety television series Exo 90:2014 with the boy band Exo and the 2015 South Korean revival of The Mickey Mouse Club (1995–1996) with Super Junior's Leeteuk, performing songs, dances, and comedy skits. Lee also participated in the concert tours SM Town Live World Tour IV (2014–2015), featuring several SM artists coming together to perform under the musical collective SM Town, and SM Rookies Show (2015–2016), held in South Korea and Thailand, in which the team covered songs by SM artists.
In July 2016, SM announced that Lee would join NCT, a boy band designed with a concept of unlimited members where smaller sub-units would debut independently and occasionally collaborate under the sub-unit NCT U. Lee debuted on July 7 with NCT's second sub-unit, NCT 127, performing their first single, "Fire Truck", on the television music program M Countdown. Upon debuting, Lee adopted the stage name Haechan, chosen by SM's founder Lee Soo-man, which means to "shine bright uprightly" in Korean. Music critics described NCT 127 as the brand's flagship and most experimental unit, as well as the first SM group to base its sound primarily on hip-hop, often blending it with R&B and electronic music subgenres such as industrial and complextro. Later that August, SM announced Haechan's addition to NCT's third sub-unit, NCT Dream, who made their debut with a performance of their single "Chewing Gum" on M Countdown on August 25. Initially established as NCT's teen unit, all members debuted as minors under a graduation system where they would leave the group upon reaching adulthood; however, the graduation concept was scrapped in 2020. Critics described NCT Dream as the unit with the most compelling narrative, remarking on how their transition from teen pop to a blend of hip-hop and R&B music reflected the members' artistic growth from adolescence to adulthood.
In the span of ten years, Haechan released over 30 studio albums and extended plays while participating in nine concert tours with the group. He contributed to the band's first full-group album, NCT 2018 Empathy (2018), and made his first appearance under NCT U with the single "Coming Home", released on December 13, 2019. Grammy.com stated that NCT became one of the most influential K-pop acts, achieving commercial success, with units like NCT Dream recording ten consecutive million-seller albums. Alongside the rapper Mark, who later departed the group in 2026, Haechan was the only NCT member to maintain a permanent position in two separate sub-units, resulting in a dense schedule. Dispatch remarked that they participated in an uncommonly high number of promotional cycles, notably releasing five albums per year in both 2021 and 2023 while switching units at roughly two-month intervals. Critics described their overlapping participation across multiple units as a "painful" side effect of the NCT system. Haechan stepped back from promotional activities thrice due to medical reasons: from December 2018 to March 2019 for a fractured tibia, in January 2023 for heart palpitations, and in January 2024 for severe tonsillitis.
After debuting, Haechan continued pursuing songwriting and began asking SM's A&R team for spare demos to practice writing top lines. He started collaborating with the songwriter and record producer Deez after working together on NCT 127's third studio album, Neo Zone (2020). The creative partnership led to the R&B tracks "Love Sign" and "N.Y.C.T", which Haechan and his former bandmate Taeil performed at NCT 127's second concert tour, Neo City – The Link (2021–2022). In March 2022, Haechan released a remake of Toy's 2001 track "Good Person" for the soundtrack of Playlist Studio's web series Ply Friends: Seoyeon University Class of '22. The following year, "N.Y.C.T" was officially released under NCT U on September 7 via the NCT Lab project. An R&B and pop track featuring guitar, bass, and brass over a piano melody, it depicts the emotions felt in moments with fans, likening the experience to walking together along the streets of New York City under the moonlight.
In March 2025, Haechan featured on "+82 Pressin'", the third single from Mark's first studio album, The Firstfruit (2025). Referencing South Korea's country calling code, the hip-hop track features lyrics written by Mark that express the duo's confidence in their capabilities, as they alternate roles with Haechan rapping and Mark singing. They first performed the song on M Countdown and later at the Tokyo dates of the SM Town Live 2025: The Culture, the Future tour. Later that May, Haechan released "A Thousand Reasons" for the soundtrack of the television series Second Shot at Love (2025). He then held a fan meeting at the Yes24 Live Hall on June 11, to commemorate his birthday. In July, Maeil Business Newspaper confirmed that he would make his solo debut in September, scheduled to follow the conclusion of group activities for NCT 127's fourth concert tour, Neo City – The Momentum, and NCT Dream's fifth studio album, Go Back to the Future, while he would continue participating in the latter's fourth concert tour, the Dream Show 4: Dream the Future (2025–2026).