Oh Eui-shik started acting on stage before landing his first screen role in the 2015 tvN series Oh My Ghostess. The next years saw him actively playing supporting roles on both the big and small screens. In 2016, he became part of the hit KBS2 sageuk Moonlight Drawn by Clouds. In 2017, he appeared in KBS2’s Fight My Way and in SBS’s While You Were Sleeping. That same year, he joined the action film Confidential Assignment. He was next cast in KBS2’s Are You Human Too in 2018 and in tvN’s Reach of Sincerity in 2019. He also returned to the silver screen with the 2019 zombie comedy film The Odd Family: Zombie on Sale. In 2020, he portrayed a teacher in the tvN coming-of-age series True Beauty.

Oh Eui-shik has a younger brother named Oh In-ha, who is a theater actor and writer.