Park Seo-joon (born Park Yong-kyu) is a South Korean actor. He is best known for his starring roles in the television series Kill Me, Heal Me (2015), She Was Pretty (2015), Hwarang: The Poet Warrior Youth (2016–2017), Fight for My Way (2017), What's Wrong with Secretary Kim (2018), and Itaewon Class (2020). He has also appeared in films such as The Chronicles of Evil (2015), Midnight Runners (2017), and The Divine Fury (2019).