Jo Hyun-jae is a South Korean actor. Jo made his entertainment debut as a singer in the four-member boy band Guardian, which disbanded after releasing their self-titled album in 1998. In 2000, after he drew popularity when he appeared in a commercial for sports drink Pocari Sweat, Jo began acting. He is best known for his leading roles in Love Letter, Only You, Ballad of Seodong, and 49 Days.