Song Kang-ho never professionally trained as an actor, beginning his career in social theatre groups after graduating from Kimhae High School. Later he joined Kee Kuk-seo's influential theatre company with its emphasis on instinctive acting and improvisation which proved Song's training ground. Although regularly approached to act in films, he always turned down the opportunity until taking a role as an extra in Hong Sang-soo's The Day a Pig Fell into the Well (1996). In the following year, after portraying one of the homeless in Jang Sun-woo's docu-drama Timeless Bottomless Bad Movie, he gained cult notoriety for his show-stealing performance in Song Neung-han's No. 3 (1997) as a gangster training a group of young recruits, winning his first Best Actor award.
Since that time he's been cast in several supporting roles before his high-profile role as Han Suk-kyu's secret agent partner in Kang Jae-gyu's blockbuster thriller Swiri (1999). In early 2000, Song became a star with his first leading role in the box office smash The Foul King, for which he reputedly did most of his own stunts. But it is with his award-winning role as a North Korean sergeant in Joint Security Area, that Song has come to the forefront as one of Korea's leading actors. Song also starred in Park Chan-wook's next feature, Sympathy for Mr. Vengeance, which centers around a father's pursuit of his daughter's kidnappers.
In 2002 Song will be starring in another major production by Myung Film, YMCA Baseball Team, about Korea's first baseball team which formed in the early 20th century. He will also star in the second film by director Bong Joon-ho (Barking Dogs Never Bite), which is based on a true story about a vicious serial killer.