Um Ki-joon (; born March 23, 1976) is a South Korean actor. He made his acting debut in 1995 in the stage play Richard III, though he later became best known as a musical theatre actor, starring in Singin' in the Rain, The Sorrows of Young Werther, Grease, The Three Musketeers, Jack the Ripper, The Count of Monte Cristo, Catch Me If You Can, and Rebecca. He also appeared in the Patrick Marber play Closer. Um's popularity increased after he began playing supporting roles in television dramas such as Life Special Investigation Team, Worlds Within, Hero, Dream High, Scent of a Woman and Phantom. He was also the leading actor in Good Job, Good Job and The Virus. He is best known for his roles in television series I'm Not a Robot (2017–2018), The Penthouse: War in Life (2020–2021) and Little Women (2022).

Career Um made his acting debut in 1995 in the stage play Richard III. After his discharge from the military in 1998, he faced a period of obscurity in Daehakro, taking on various roles in both large and small productions, starting with the musical "Gwanggaeto the Great." However, it was in the musical in Singin' in the Rain, where his true talent shone, propelling him to stardom with his portrayal of Dong-hyeon. Subsequently, he appeared in productions such as The Sorrows of Young Werther, Grease and Hedwig and the Angry Inch.

In 2004, Um made a return to the theater stage with play Male Impulse.

In 2006, Um made his television debut in Drama City - Who Loved Her? directed by Lee So-yeon. The following year, he worked with Lee So-yeon again in Drama City - The Grim Reaper with Amnesia. Um also appeared in Kimchi Cheese Smile, as Ki-jun, Shin Goo's eldest son, who rents the second floor of his friend Byeong-jin's house. He is a man with a sly personality who is messy at home and neat and tidy outside.

In 2008, Um worked with Lee So-yeon again in Drama City - Secret, Only You Don't Know. He played the role of unknown artist Park Hyeong-joo, who is torn between his beloved wife and his male lover. Um became a TV star as the charming and grumpy boy Son Gyu-ho in the drama Worlds Within.

In 2009, Um made a return to the theater stage with Maxim Gorky's play The Lower Depths which features characters from the lower echelons of society including a fallen nobleman, a woman suffering from a terminal lung disease, and an alcoholic actor, he takes on the role of Satine, a once-intellectual turned conman. The play is set in Russia during the 1890s, a time marked by increasing social disparity and economic depression. It was performed at the Seoul Arts Center Towol Theater from February 14 to March 22.

In 2010, Monte Christo.

Um played the villain in his first film Man of Vendetta, opposite Kim Myung-min. This was followed by a role as Lee Ki-cheol, a detective investigating serial murders in horror film Killer Toon, opposite Lee Si-young.

In 2016, Musical Matahari.

In 2017, Um played the villain in the hit legal thriller Innocent Defendant.

In 2018, he reunited with the director and writer of Innocent Defendant in medical drama Heart Surgeons.

In 2020, he appeared in TV series The Penthouse: War in Life as Joo Dan-tae, the main villain and a scheming real estate genius. The series aired on SBS TV from October 26.

Um reprised in his role of Werther in the 20th anniversary of the Korean musical "Werther".

In 2021, Um signed a contract with Your Entertainment. It was founded by a manager who has been with him since his debut.

In 2023, He appeared in 10th anniversary of musical The Days.

Personal life In May 2024, it was reported that Um will tie the knot with a non-celebrity partner in December. The couple married on December 22 in Seoul.

Filmography Film Year Title Role Notes 2010 Man of Vendetta Choi Byeong-chul Villain and Widow Representative Ha Cameo appearance Finding Mr. Destiny Kim Jong-wook 2013 Killer Toon Lee Ki-cheol 2022 It's Alright TVING Shorts Film 2026Tokyo Burst: Crime CityJapanese–Korean film

Television series Year Title Role Notes 2006 Drama City:"Who Loved Her?" Park Cheol-ho 2007 Drama City:"Grim Reaper with Amnesia" Dong-wook Kimchi Cheese Smile Um Ki-joon 2008 Drama City:"Secret, Only You Don't Know" Park Hyeong-joo Life Special Investigation Team Park Chan-ho Worlds Within Song Gyu-ho 2009 Good Job, Good Job Choi Seung-hyun Hero Kang Hye-sung 2011 Dream High Kang Oh-hyuk Miss Ripley Prosecutor Cameo (episode 14) Scent of a Woman Chae Eun-suk Can't Lose Cha Seok-hoon Cameo (episodes 14–17) 2012 Phantom Jo Hyun-min 2013 The Virus Lee Myung-hyun I Can Hear Your Voice Public defender Um Ki-joon Cameo (episode 14) 2014 Golden Cross Michael Jang 2015 The Man in the Mask Kang Hyun-woong 2017 Innocent Defendant Cha Sun-ho / Cha Min-ho I'm Not a Robot Hong Baek-kyun 2018 Heart Surgeons Choi Suk-han 2020–2021 The Penthouse: War in Life Joo Dan-tae / Baek Jun-gi Season 1–3 2022 Shooting Stars Yoon Jang-seok Cameo (episode 13) Little Women Park Jae-sang 2023–2024 The Escape of the Seven Matthew Lee / K / Sim Jun Seok

Web series Year Title Role 2016 Nightmare Teacher Han Bong-gu

Television show Year Title Role Notes 2017–2018 Wizard of Nowhere Cast Member 2021 We Don't Bite: Villains in the Countryside Cast Member with Yoon Jong-hoon and Bong Tae-gyu 2025Before It's Too Late ShalaShalaCast Memberwith Sung Dong-Il Kim Kwang-kyu Shin Seung-hwan and Jang Hyuk

Music video appearances Year Song Title Korean Title Artist 2007 "Goodbye, 20 Years Old" Toy "Three People" Lee Ki-chan 2015 "April Snow" Huh Gak

Stage Concerts +Concert performancesYearTitleRoleTheaterDateEnglishKorean2007Hedwig Concert with John Cameron Mitchell존 카메론 미첼과 함께하는 헤드윅 콘서트HedwigJamsil Indoor GymnasiumMay 27 – June 5 2014 Eom-Yu-Min-Beop Premium One Concert 엄유민법 프리미엄 원(premium one) 콘서트Bunkamura Orchard Hall in TokyoSeptember 29–30

Musical