Jang Hyuk (born Jung Yong-joon on December 20, 1976) is a South Korean actor. He is best known for his leading roles in the films Volcano High (2001) and Windstruck (2004), and the television dramas Successful Story of a Bright Girl (2002), The Slave Hunters (2010), Deep Rooted Tree (2011), and Fated to Love You (2014).
Jung Yong-joon spent most of his childhood and adolescence in his birthplace Busan, before making his acting debut in 1997 in the television drama Model under the stage name Jang Hyuk. Besides the teen series School and a minor role in the little-seen film Zzang (The Best), Jang appeared in the music video To My Mother, the 1999 debut single of popular boyband g.o.d. He also acted in several music videos from his rap album, released in 2000 under the name TJ Project. His career first began to take off in 2001 when he was cast in the lead role of the special-effects extravaganza Volcano High together with actress Shin Min-ah. His acting in the eccentric role drew praise from fans and critics.