Kang Yoo-seok debuted as an actor in 2018 with a guest role in the OCN drama God’s Quiz: Reboot. This was followed by several more supporting roles in a couple of TV series including tvN’s Melting Me Softly and Star-Up, which aired in 2019 and 2020, respectively. Later in 2020, he landed his first main role in the movie The Interviewees. He also became part of the main cast of the 2020 web series Growing Season. In 2021, he starred in Viki’s boy love drama Light on Me. In 2023, he joined Lee Seon-kyun and Moon Chae-won in the SBS thriller Payback.

Kang Yoo-seok attended the Korea National University of Arts.