He made his acting debut in 2011, and appeared in over 30
short films as a student of
Korea National University of Arts. The then-unknown actor rose to fame in 2014 with a supporting role in the popular workplace cable series
Misaeng: Incomplete Life. In 2015, he starred in leading roles in
indie hit
Socialphobia and the romantic comedy ''
Ex-Girlfriends' Club''. In the same year, he also appeared as one of the six main leads in
SBS's 50-episode historical drama
Six Flying Dragons playing a master swordsman. Byun then starred alongside
Kim Yoon-seok in the fantasy drama film
Will You Be There?. In 2018, he starred in the hit drama
Mr. Sunshine, which became one of the
highest-rated dramas in Korean cable television history. In 2021, Byun starred in
Lee Joon-ik's black-and-white historical film
The Book of Fish, for which he was nominated for the
Baeksang Arts Award for Best Actor – Film. In 2023, Byun was chosen as the representative of "Next Actor" in the 11th Muju Film Festival which held in June 2–6, 2023. His works and career's history were exhibited in Muju Choibuk Art Museum during the festival. In 2022, Byun was reported to star alongside
Song Kang-ho in Uncle Samsik. Set in the 1960s, the series depicts the intertwined story of two men, exploring themes of pride, greed, and their camaraderie. Shin Yeon-shick wrote and directed the series. It was released worldwide on
Disney+ and on
Hulu in the USA from May 15 to June 19, 2024. ==Personal life ==