Kim Jeong-hoon (also known as John Hoon) is a South Korean actor and singer best known for his affiliation with the South Korean group UN, and his appearance in the Korean drama, Princess Hours. He portrays an as-yet-to-be-specified role in Steven S. DeKnight's Pacific Rim: Uprising.
Hoon debuted as a member of Korean duo UN in 2000, an acronym for "United N-generation". After six years of success, the duo officially announced that they were disbanding in September 2005, and Kim announced that he was going to pursue an acting career instead, as the conditions of the Korean music industry preventing him from pursuing music he truly wanted to.
By 2005, Hoon began working in Korean dramas. He starred in the sitcom Orange and A Man and a Woman in 2004. His leading role in Princess Hours, co-starring Yoon Eun-hye and Ju Ji-hoon, as Yul --- a nineteen-year-old prince, is considered a major breakthrough role.
After serving two years in the military, Kim returned to the public eye February 28, 2011. He has since appeared in a number of dramas. In 2016, Kim was cast in the Chinese historical drama God of War, Zhao Yun along with Girls' Generation's YoonA, as Gao Ze.
- According to some sources, Kim Jeong-Hoon's appearance in Pacific Rim: Uprising is a cameo.
- On April 28, 2009, he left the public for mandatory military service of two years.
- Kim Jeong-Hoon initially wanted to be a laboratory researcher.