Seo In-guk (서인국; 徐仁國) is a South Korean singer and actor born on October 23, 1987, in Ulsan. Coming from a modest background, he dreamed of becoming a singer from a very young age. After several failed auditions—largely due to his weight—he finally made a name for himself by winning the first season of the show in 2009. Superstar K, which launched his musical career.
He began his acting career in 2012 with Love Rain, before achieving massive success thanks to the cult drama Reply 1997, where his duet with Jung Eun-ji captivated the audience. He then went on to play leading roles in Master's Sun, High School King of Savvy, The King's Face, Hello Monster, Squad 38, Shopping King Louie and The Smile Has Left Your Eyes. He also made a name for himself in film in No Breathing, Pipeline and Project Wolf Hunting.
In 2021, he regained international fame thanks to the fantasy romance Doom at Your Service, before playing the former profiler Nam Han-jun in Café Minamdang and then the hero of Death's Game, an adaptation of the famous webtoon.
In 2026, he continued his momentum with several major projects. He played the lead role in Boyfriend on Demand, in which he plays Park Gyeong-nam, as well as that of See you at work tomorrow!. He also joins the fantasy series Twelve in the role of Won Seung, inspired by the Monkey King, and is set to appear in Office Worker Who Sees Fate, in which he plays Choi Yeong-hun.
A well-rounded artist who can effortlessly switch between romance, comedy, thrillers, and fantasy, Seo In-guk has established himself as one of the most versatile and beloved figures in the South Korean entertainment industry.
