Lee Jong-won debuted as an actor in the 2018 web series Back to the Future. That same year, he appeared in the independent film Regret. In 2020, he played supporting roles in the tvN drama My Unfamiliar Family and in the MBC series The Spies Who Loved Me. He also starred in Olleh TV’s In Your Dream, opposite Bae Nuri, as well as in the web dramas XX and Amanza. In 2021, he became part of the second season of the hit tvN series Hospital Playlist. In 2022, he was cast as one of main characters in the MBC fantasy drama Golden Spoon.

Lee Jong-won fulfilled his mandatory military service prior to his entertainment industry debut.