Sithathoriunet was an Ancient Egyptian king's daughter of the 12th Dynasty, mainly known from her burial at El-Lahun in which a treasure trove of jewellery was found. She was possibly a daughter of Senusret II since her burial site was found next to the pyramid of this king. If so, this would make her one of five known children and one of three daughters of Senusret II—the other children were Senusret III, Senusretseneb, Itakayt and Nofret.
Sithathoriunet was buried in the Kahun pyramid complex. She must have died while Amenemhat III was pharaoh, since objects with his name were found in her tomb. Her name and titles survived on her canopic jars and on an alabaster vessel found in her tomb.
The tomb was excavated in 1914 by Flinders Petrie and Guy Brunton. It had previously been robbed in antiquity but a niche in the burial site escaped the looters' attention. In this niche were found remains of several boxes filled with jewellery and cosmetic objects, such as razors, a mirror and vases. The jewellery found there is considered to be among the highest quality examples ever found in Ancient Egyptian tombs.