Empress Cao may refer to:
China These empresses had the surname Cao (). Empress Cao (Han dynasty) (died 260), empress of the Han dynasty Empress Cao (Dou Jiande's wife) (fl. 621) Empress Cao (Huang Chao's wife) (died 884) Empress Dowager Cao (Li Cunxu's mother) (died 925), empress dowager of Later Tang Empress Cao (Li Siyuan's wife) (died 937), empress of Later Tang Empress Cao (Song dynasty) (1016–1079), empress of the Song dynasty
Vietnam These empresses received the posthumous name Empress Cao (Cao Hoàng hậu, ; "High Empress"). Thừa Thiên (empress) (1762–1814), first wife of Emperor Gia Long Thuận Thiên (Nguyễn dynasty empress) (1769–1846), second wife of Emperor Gia Long
See also Empress Gao (disambiguation)