Kim Dong-wook first gained prominence in 2007 after playing a supporting role in the hit MBC romantic comedy Coffee Prince. In 2009, he starred in the movie Take Off, which recorded over eight million theater admissions. His performance in the movie won him Best New Actor trophies at the 12th Director’s Cut Awards and the 7th Max Movie Awards. The movie was also named Best Film at the 46th Baeksang Arts Awards and the 17th Chunsa Film Art Awards. In 2012, he played the role of an obsessed and tormented king in the erotic period movie The Concubine. In 2017, he was cast in the MBC workplace romantic comedy Radiant Office, which earned him a nomination for an Excellence Award at the MBC Drama Awards. He next starred in the 2017 fantasy action film Along with the Gods: The Two Worlds, in which he took home several Best Supporting Actor citations. He reprised his role in the second installment of the movie franchise titled Along with the Gods: The Last 49 Days. In 2019, he received the Daesang at the MBC Drama Awards for his performance in the series Special Labor Inspector Jo.

On August 30, 2012, Kim Dong-wook enlisted for his mandatory military service. He served as a riot policeman for the Seoul Metropolitan Police Agency. He was discharged on May 29, 2014.