Park Won-sang made his acting debut in director Im Soon-rye’s critically acclaimed first film Three Friends in 1996. In 2001, he reunited with Im Soon-rye in her sophomore film Waikiki Brothers. In 2002, he acted alongside Kam Woo-sung and Uhm Jung-hwa in the erotic movie Marriage Is a Crazy Thing, which was followed by an appearance in the 2003 psychological horror film The Uninvited. In 2011, he starred with Ahn Sung-ki in the courtroom drama Unbowed, which took home the Best Film citation at the 48th Baeksang Arts Awards. In 2013, he became part of the hit comedy-drama movie Miracle in Cell No. 7. In 2015, he joined the historical drama film The Throne by director Lee Jun-ik. It was named Best Film at the 35th Korean Association Film Critics Awards. Aside from films, Park Won-sang’s acting credits also include theater plays such as The Seagull and Noises Off. He is also active as a supporting actor on television.

Park Won-sang studied German language and literature at Soongsil University.