Park Ki-woong made his entertainment debut in the 2004 K2 music video “Giving You Love,” then launched his acting career in 2005. He rose to stardom for being the “mill dance (맷돌춤)” guy in a 2006 SKY PMP Phone commercial. After a series of supporting roles on TV and film, Park starred in his first leading role in the 2007 romantic comedy My Tutor Friend 2, but the film wasn’t commercially successful. In 2008, he became the honorary ambassador of his hometown Andong.

The Slingshot (2009) gave Park his first acting accolades. Critics and viewers praised his portrayal of an autistic genius who transforms into the best stock market analyst in the country. His other notable roles include an invading Manchurian prince in period action film War of the Arrows (2011); a sociopathic Japanese officer in colonized Korea in Bridal Mask (2012); and an elite North Korean spy undercover as a rock musician in box office hit Secretly, Greatly (2013).