Empress Wang (王皇后, personal name unknown) (8 BC – AD 23), formally Empress Xiaoping (孝平皇后), formally during her father Wang Mang's Xin dynasty Duchess Dowager of Ding'an (定安太后) then Princess Huanghuang (黃皇室主), was an empress during the Han Dynasty and the last empress of the Western Han Dynasty. She was the daughter of the eventual usurper Wang Mang, who established the Xin Dynasty. Her husband was Emperor Ping.