Cai Mao (?-208) was an officer under Liu Biao. He came from a noble family in Jing and was the younger brother of Liu Biao's second wife. His plot to assassinate Liu Bei in order to make Liu Cong successor ended in failure. He excelled as a naval commander. At the Battle of Chi Bi, commanding Cao Cao's Armada alongside his uncle Zhang Yun, he was executed by Cao Cao in a ploy by Zhou Yu.