Kim Jeong-hoon, known more commonly by the stage name John Hoon, is a South Korean singer and actor. He was born on January 20, 1980, in Jinju, South Korea. He began his music career in 2000 as part of the South Korean duo UN (United N-generation), which quickly gained popularity with their debut single "Voice Mail." The duo enjoyed six years of success before disbanding in 2005, leading John Hoon to pursue a solo music career. This began with the release of his first mini-album 5 Stella Lights in 2006. He followed this with a series of successful singles throughout 2007, including "Sad Song" and "Boku Wa Kimi Wo Aishiteru." His first full-length album, Bokutachi Itsuka Mata... ETERNITY, was released later in 2007, and it was acclaimed by both critics and fans. Throughout his career, John Hoon continued to release music, including his second album Kyo mo Atarashii Yume wo Miru (2008), and the well-received single "Blue Moon" in 2009. He also released his third album Machi in 2010, which peaked at number 18 in the Oricon charts. His single "Present" followed in 2011, and then his fourth album Voice in 2012. John Hoon was also engaged in a prolific acting career, appearing in shows like Dummy Mommy and The Three Witches, as well as his Hollywood debut in the 2018 film Pacific Rim: Uprising.