Ryeoun made his acting debut in 2017 with appearances in MBC’s You’re Too Much and in SBS’s Temperature of Love. In 2018, he starred in the web dramas Doo Teob’s Pretty Easy School Life and Instant Romance. In 2019, he portrayed Kwon Nara’s younger brother in the KBS2 medical series Doctor Prisoner. In 2019, he became part of MBC’s 365: Repeat the Year and JTBC’s Eighteen Again. In 2020, he joined the KBS2 weekend drama Oh! Samkwang Villa, which earned him a Best New Actor nomination at the KBS Drama Awards. In 2021, he was cast in the TVING series Adult Trainee. In 2022, he played a supporting role in the SBS crime thriller Through the Darkness, which won him Best New Actor at the SBS Drama Awards.