Lady Qi (祁夫人, fl. 316–324), also known as Lady Wei (惟氏), was the wife of Tuoba Yituo and a regent of Dai in the Sixteen Kingdoms period during the minority of her son between 321 and 324. As the rulers of Dai were posthumously honoured as emperors during the Northern Wei, she is also referred to as Empress Dowager Qi (皇后祁) or Empress Dowager Wei (皇后惟) in some historical records.
After overthrowing Tuoba Yulü in a bloody coup, Lady Qi ruled Dai for roughly four years between 321 and 324 behind her son, Tuoba Heru. During her brief rule over the state, Dai was described as a 'queendom' (女國) by the people of Later Zhao. Following Tuoba Gui's claimant of the imperial title in 399, Lady Qi was posthumously honoured as Empress Huan (桓皇后).