Song Kang-ho never received formal training as an actor, but instead began his career in social theater groups after graduating from Kimhae High School. He later joined Kee Kuk-seo's influential theater company, which emphasized instinctive acting and improvisation, serving as his training ground.
Although frequently approached to act in films, Song consistently declined opportunities until taking a small role as an extra in Hong Sang-soo's The Day a Pig Fell Into the Well (1996). The following year, he gained recognition for his scene-stealing performance in Neung-han Song No. 3 (1997) as a gangster training a group of young recruits, earning his first Best Actor award.
Following this success, Song was cast in several supporting roles before landing a high-profile part as Han Suk-kyu's secret-agent partner in Kang Je-kyu's blockbuster thriller Shiri (1999). Early in the 2000s, Song became a star with his first leading role in the box office smash The Foul King (2000),for which he reportedly performed most of his own stunts.
However, it was his award-winning role as a North Korean sergeant in Joint Security Area (2000) that cemented his status as one of Korea's leading actors. Song also starred in Park Chan-wook's Sympathy for Mr. Vengeance (2002),which revolves around a father's pursuit of his daughter's kidnappers.
In 2002, Song starred in another major production, YMCA Yagudan (2002),about Korea's first baseball team, which formed in the early 20th century. He gained international recognition with the film The Host (2006),which reunited him with director Bong Joon Ho. With Snowpiercer (2013),his third collaboration with Bong, he made his debut in an English-language film with international theatrical distribution.
In 2008, Song starred in Kim Jee-woon's film The Good the Bad the Weird (2008),where he played Tae-goo, the motorcycle-riding, walther-wielding counterpart to Tuco from "The Good, the Bad and the Ugly".
In 2015, Song Kang-ho worked on 'The Throne', a period drama of palace intrigues par excellence, whose film was nominated for best non-English-language film and costumes at the Satellite awards that year.
Already in 2016, he made his fourth collaboration with Korean director Kim Jee-woon and starred in the critically acclaimed film "The Empire of Shadows", a period drama with a background of espionage intrigue, boasting a very good technical bill.