Jung Jae-young started his acting career with a minor role in the 1996 movie The Adventures of Mrs. Park and has since appeared in a number of films and series. In 2003, he played the role of a death row convict turned soldier in the movie Silmido. He was named Best Supporting Actor at the 25th Blue Dragon Film Awards for his performance in the movie. In 2009, he headlined the film Castaway on the Moon, in which he took home the Best Actor trophy at the 32nd Golden Cinematography Awards. He was also nominated for Best Actor at the 46th Baeksang Arts Awards for his work in the film. In 2010, he was cast in the mystery thriller film Moss, which was based on the popular webtoon of the same title. The movie won him Best Actor at the 31st Blue Dragon Film Awards and the 19th Buil Film Awards. He once again collected Best Actor trophies from various local and international award-giving bodies for the 2015 movie Right Now, Wrong Then.

Jung Jae-young is also recognized for his work in television dramas. In 2015, he was nominated for a Top Excellence Award at the KBS Drama Awards for the political drama Assembly. In 2018, he won a Top Excellence Award at the MBC Drama Awards for Investigation Couple.