The Duo (Korean: 짝패; RR: Jjakpae) is a 2011 South Korean historical drama series, starring Chun Jung-myung, Lee Sang-yoon, Han Ji-hye and Seo Hyun-jin. It aired on MBC from February 7 to May 24, 2011, on Mondays and Tuesdays at 21:55 for 32 episodes.

Filmed at MBC Dramia in Gyeonggi Province, the series examines how class determines fate during the Joseon era through two men who swap lives. Switched at birth, Chun-doong and Gwi-dong grow up living each other's lives. Nobleman's son Chun-doong endures great hardships in the lowest caste of society, and becomes a vigilante who steals from the rich. Beggar's son Gwi-dong grows up in a wealthy noble family, and becomes a police chief. Living on opposite sides of the law, their paths cross again when they both fall for the same woman; played by Chun, Lee and Han respectively.