Jeong Yun-o (; born Jeong Jae-hyun (), February 14, 1997), known professionally as Jaehyun, is a South Korean singer and actor. He rose to prominence as a member of the K-pop boy band NCT and its sub-units NCT 127 and NCT DoJaeJung.
Born in Seoul and raised between South Korea and the United States, Jaehyun started training under SM Entertainment in 2012 and began his career in 2013 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, which went on to achieve commercial success and become an influential K-pop act. Following the release of his first standalone singles, "Forever Only" (2022) and "Horizon" (2023), Jaehyun's debut studio album, the R&B record J (2024), reached number three on the Circle Album Chart and sold over 450,000 copies in South Korea, with its lead single, "Smoke", marking his first top-five entry on the Circle Digital Chart.
On television, Jaehyun hosted the music program Inkigayo from 2019 to 2021 and first ventured into acting with a leading role in the college romance series Dear.M (2022). He made his film debut in the mystery thriller You Will Die in 6 Hours (2024). Jaehyun has also served as a global ambassador for the Italian fashion house Prada since 2022.
Life and career 1997–2012: Early life and musical beginnings Jaehyun was born on February 14, 1997, in Seocho District, Seoul, South Korea. Although he was born with the name Jeong Jae-hyun (), he later legally changed his name to Jeong Yun-o (). At the age of five, Jaehyun moved to Connecticut, USA with his parents, where he went by the English name Jay Jeong. As a result, he is fluent in both English and Korean. He revealed that while studying in Connecticut, he was the only Asian student at school. Jaehyun returned to South Korea at the age of ten, and said that he struggled adapting back to Korean culture.
Jaehyun trained in Taekwondo and received a Black belt. He later became interested in music at a young age due to his parents' influence; he learned to play the guitar and the piano, and eventually began singing during his middle school. His grandmother, a retired professional dancer, was also his guide during dance training. He was also inspired to pursue music by his elementary school teacher. Jaehyun attended Shindong Middle School and Apgujeong High School and later transferred to the School of Performing Arts Seoul in his second year of high school and graduated in 2016. He used to be a student council president.
2013–2018: SM Rookies and NCT Jaehyun was cast by SM Entertainment in 2012, discovered by street scouts in front of his school. He auditioned with a performance of "Mama" by Exo. On December 9, 2013, he was introduced as a member of the pre-debut trainee team SM Rookies. In 2014, he participated with fellow NCT members on the show Exo 90:2014, where they performed songs from the 1990s. From January 21 to July 1, 2015, he and groupmate Doyoung were hosts of the program Show Champion. In July 2015, he and groupmate Ten both competed in Hope Basketball All-Star. In December 2015, Jaehyun performed "A Whole New World" on Disney Channel Korea's The Mickey Mouse Club.
In April 2016, Jaehyun officially debuted as a member of NCT's sub-unit, NCT U, with the singles "The 7th Sense" and "Without You". On July 10, he made his debut as a member of NCT 127 with their first EP, NCT#127. In March 2017, Jaehyun joined the radio show NCT Night Night as a DJ alongside fellow member Johnny. In November 2017, Jaehyun and Dear released the song "Try Again" for the project SM Station. In December, he featured in the music video for Wendy and Baek A-yeon's "The Little Match Girl".
2019–2023: Television work and standalone releases In October 2019, Jaehyun became one of three hosts for the South Korean music program Inkigayo alongside Minhyuk and Naeun, hosting the show every Sunday. On September 4, 2020, it was confirmed that Jaehyun would make his acting debut as Cha Min-ho – a second-year computer science student at Seoyeon University, in the KBS2 drama Dear.M, which was to be released in 2021. The airing of the drama was postponed indefinitely after lead actress Park Hye-su was accused of school bullying. After a nearly two-year delay, the first six episodes of Dear.M were released globally on June 29, 2022, through the streaming service Viki. Its following episodes were released on July 6, 2022.
On August 18, 2022, Jaehyun released his first single "Forever Only" as part of NCT Lab. "Forever Only" was described as an R&B song and featured lyrics written by Jaehyun. It received positive reviews from critics and debuted at number 14 on the United States' Billboard World Digital Songs and at 120 on South Korea's Circle Digital Chart. On March 9, 2023, Jaehyun was confirmed to debut alongside fellow NCT members Doyoung and Jungwoo in the new fixed sub-unit NCT DoJaeJung. They released their first extended play (EP) Perfume on April 17, 2023.
On August 8, he released his second solo single "Horizon" under the now-reconstructed NCT Lab. The song is described as a romantic R&B/Soul track that Jaehyun wrote and composed. It debuted at number 38 on the Circle Digital Chart.
2024–present: J and military enlistment In August 2024, SM announced that Jaehyun would debut as a soloist with his first studio album J. The eight-track album was released on August 26, and included Korean and English versions of the title track "Smoke". Jaehyun actively participated in the production of the album, not only in the songwriting process but also in shaping its direction and title. Among the eight tracks, he contributed to create five songs on the album. Jaehyun participated in writing the lyrics of his title track "Smoke", composition and lyrics of "Roses" and "Flamin' Hot Lemon" with Azad of American duo Emotional Oranges, as well as being the sole lyricist of "Dandelion" and "Can't Get You". Jaehyun stated that "for each and every track, I really wanted to have a reason why it's in the first album. I had a different concept and image of each track for this album, and I really wanted to make it feel classic so you could listen to it later on. That was the thought".
Before the album's release, Jaehyun pre-released two songs off the album as a digital single, "Roses" and "Dandelion" on August 12. On the day of the album's release, Jaehyun hosted a listening party titled Jaehyun Vol. 1. The album debuted at number three on the Circle Album Chart, number 11 on the US Heatseekers Albums (Billboard), number 18 on the US Top Albums Sales (Billboard) and number seven on Japanese Albums (Oricon). "Smoke" also debuted at number one on Circle Digital Chart, two weeks in a row upon release. On September 7, "Smoke" achieved a first place win on South Korean music program Show! Music Core. It earned a nomination for Millions Top 10 at the 2024 Melon Music Awards.
In September 2024, SM announced that Jaehyun would hold his first concert, titled Mute, at the Olympic Handball Gymnasium in Seoul on October 26 and 27, 2024, before enlisting to fulfill his mandatory military service later that November. Both dates were sold out, and the final performance was broadcast live through Beyond Live and Weverse. On October 24, he released the single "Unconditional", an R&B and pop track driven by a funky bassline expressing unconditional feelings toward a loved one, which he debuted live at the concert. That same month, Jaehyun made his feature film debut, starring in the mystery thriller You Will Die in 6 Hours () alongside Park Ju-hyun and Kwak Si-yang. Based on the novel of the same name by the Japanese author Kazuaki Takano, the film follows a woman trying to prevent her own death after a man predicts that she has only six hours to live. It won the Audience Award at the 28th Bucheon International Fantastic Film Festival, ranked first in advance ticket sales for independent and art films, and was pre-sold to 76 countries.
Jaehyun served in the army's military band from November 4, 2024, to May 3, 2026. He performed the official song for the 2025 Armed Forces Day, appearing in its promotional music video. While he was enlisted, Emotional Oranges released the dance, pop, and R&B single "Call It Off" featuring Jaehyun from their album Orenji on April 25, 2025, marking their second collaboration after "Flamin' Hot Lemon". Later that May, during the initial television broadcast of Dear.M on KBS Joy, Jaehyun's song "Look at Me" was released as part of the series's soundtrack. After his discharge, he embarked on his first concert tour, titled Mono, visiting five cities across Asia from June to July 2026. Ticket sales for the Seoul concerts took place on May 11 and 12, with all dates quickly selling out. At the show, Jaehyun performed his own songs as well as tracks by NCT and previewed the single "99 Degrees", a sentimental ballad released on July 10 that uses 99 degrees, just below the boiling point of water, as a metaphor for discovering perfect love through imperfection. In July, over ten years after his debut, it was announced that Jaehyun had renewed his exclusive contract with SM.
Other ventures Endorsements Jaehyun began collaborating with the Italian fashion house Prada in 2021, becoming the first person to host an official live-stream of a Prada runway show via a personal social media account that September. Prada officially appointed Jaehyun as its global ambassador in June 2022, citing his sophisticated image, distinct fashion sense, and strong influence across their previous collaborations. In January 2023, he became the first Korean celebrity to star in a global campaign for the brand, photographed by David Sims for the Spring/Summer 2023 collection. Through his partnership with Prada, Jaehyun has since attended numerous fashion shows in Milan and brand pop-ups globally, starred in fashion films, and featured in fashion magazines. The collaboration also extended into his music career: they worked together on a music video for his song "Can't Get You", and he mentioned the brand in the lyrics of "Unconditional". South Korean publications noted that items worn by Jaehyun sold out, and that his appearances at fashion shows drew large crowds, contributing in driving the attention of Korean consumers toward Prada.
In 2024, Jaehyun became the brand ambassador for the Indonesian snack brand TicTac, the South Korean cosmetics brand Clio Cosmetics, and the Thai hair care brand Go Hair. He has also partnered with the Anglo-French perfume house Creed since June 2026.
Philanthropy In March 2020, Jaehyun joined an awareness campaign organized by the non-governmental organization Sports Doctors to support medical staff working during the COVID-19 pandemic. In March 2025, Jaehyun donated million to the Hope Bridge Korea Disaster Relief Association to aid recovery efforts for the wildfires that broke out that month.
Discography
Studio albums + List of studio albums, with selected details, chart positions, sales figures, and certifications Title Details Peak chart positions Sales Certifications KOR JPN JPNHot USHeat USSales J Released: August 26, 2024 Labels: SM, Kakao Formats: CD, digital download, LP, streaming 3 7 7 11 18 KOR: 451,249Sources: JPN: 13,909Sources: KMCA: Platinum
Singles As lead artist + List of singles as lead artist, with year of release, selected chart positions, and associated album Title Year Peak chart positions Album KORPeak chart positions on the Circle Digital Chart: "Forever Only": "Horizon": "Smoke": UKDLPeak chart positions on the UK Singles Downloads Chart: "Smoke": USWorldPeak chart positions on the US Billboard World Digital Song Sales: "Forever Only": VIEPeak chart positions on the Billboard Vietnam Hot 100: