Beihai Commandery (北海郡) was a commandery of Qing Province on the north-eastern Shandong Peninsula. Its territory lay along the Bohai Gulf and the inland plains around modern Qingzhou and Weifang, including counties such as Gaomi.
In the late Eastern Han Beihai became known both for warfare and for learning. Kong Rong served as Administrator of Beihai and defended the commandery against Yellow Turban remnants, famously calling on Liu Bei for aid. The great Confucian exegete Zheng Xuan was born at Gaomi in Beihai, and the region produced other officials and scholars mentioned in the histories. During the struggles between Yuan Shao, Gongsun Zan, and Cao Cao, Beihai and its coastal counties suffered repeated campaigning but remained an important intellectual and administrative centre in north-east China.