Go Chang-seok began acting in theater before transitioning to television and films. He made his feature film debut in the movie The Last Wolf in 2004. In 2008, he was cast in director Jang Hoon’s action movie Rough Cut, which earned him Best Supporting Actor nominations at the 29th Blue Dragon Film Awards and the 7th Korean Film Awards. In 2010, he won Best Supporting Actor at the 18th Chunsa Film Art Awards for the drama film A Barefoot Dream. In 2010, he reunited with director Jang Hoon for the action film Secret Reunion, where he played a Vietnamese gang boss. In 2011, he took home the Best Supporting Actor trophy at the 20th Buil Film Awards for the war film The Front Line. That same year, he scored a Best Supporting Actor nomination at the 48th Grand Bell Awards for the period movie The Showdown. In 2013, he became part of the KBS2 dramas Ad Genius Lee Tae-baek and Good Doctor, in which he was nominated for Best Supporting Actor at the KBS Drama Awards.

Go Chang-seok is married to actress Lee Jung-eun. She is not to be confused with the Parasite actress who bears the same name. Go Chang-seok’s wife and daughter appeared as his character’s family in The Showdown.