Gyebaek (Korean: 계백; Hanja: 階伯) is a 2011 South Korean period drama series, starring Lee Seo-jin, Cho Jae-hyun, Song Ji-hyo and Oh Yeon-soo . It aired on MBC from July 23 to November 22, 2011 on Mondays and Tuesdays at 21:55 for 32 episodes. The series was filmed at MBC Dramia in Gyeonggi Province.