Jo Hyun-jae debuted as a member of the South Korean boy group Guardian. The four-member group disbanded after the release of their self-titled album in 1998. Jo Hyun-jae then pursued acting after his appearance in a commercial for a sports drink drew attention in 2000. His first acting roles were in the dramas KAIST and Golden Pond. In 2003, he was cast in the SBS series First Love, in which he won the New Star Award at the SBS Drama Awards. That same year, he made his movie debut in Untold Scandal, which was the fourth highest-grossing Korean film of 2003. In 2005, he headlined the sageuk Ballad of Seodong, opposite Lee Bo-young. He was named Most Popular Actor for TV at the 42nd Baeksang Arts Awards for his work in the drama. In 2011, he became part of the hit SBS fantasy romance 49 Days. His popularity in the drama won him the Hallyu Star Award at the 19th Korea Culture and Entertainment Awards. In 2018, he bagged the Best Actor trophy at the 26th Korea Culture and Entertainment Awards for his performance in the SBS drama Let Me Introduce Her.
On March 24, 2018, Jo Hyun-jae married former professional golfer Park Min-jung after three years of dating. They welcomed their son on November 20, 2018.