Yoo Yeon-seok made his acting debut in the acclaimed 2003 film Oldboy as the younger counterpart of Yoo Ji-tae’s character. In 2013, he received love from the audience for his role as Chilbong in the popular tvN series Answer Me 1994. In 2014, he starred in the period film The Royal Tailor, which won him Best New Actor at the 2015 Golden Cinema Film Festival. He was also nominated for Best Supporting Actor at the 51st Baeksang Arts Awards and the 52nd Grand Bell Awards for his performance in the movie. In 2016, he acted alongside Han Seok-kyu and Seo Hyun-jin in the hit SBS series Romantic Doctor Teacher Kim, which earned him an Excellence Award at the SBS Drama Awards. In 2018, he played a ruthless samurai in the top-rating tvN period drama Mr. Sunshine, which gave him acting trophies at that year’s Asia Artist Awards and The Seoul Awards. In 2020, he reunited with the Answer Me PD-writer duo of Shin Won-ho and Lee Woo-jung in tvN’s Hospital Playlist.

Yoo Yeon-seok entered the South Korean Air Force for his mandatory military service after his debut in Oldboy. He graduated from Sejong University with a degree in film arts.