Xin Zhui (died 163 BCE); also known as Lady Dai or Marquise of Dai; was the wife of Li Cang; the Marquis of Dai; during the Han Dynasty (206 BCE - 220 CE). She gained fame more than 2;000 years after her death; when her tomb was discovered inside a hill known as Mawangdui; in Changsha; Hunan; China.

After opening the tomb; workers discovered her exceptionally preserved remains alongside hundreds of valuable artifacts and documents. Her body and belongings are currently under the care of the Hunan Provincial Museum; which has allowed occasional international exhibits.