St. Mary's Priory, North Berwick, was a monastery of nuns in medieval East Lothian, Scotland. Founded by Donnchad I, Earl of Fife (owner of much of northern East Lothian) around 1150, the priory lasted for more than four centuries, declining and disappearing after the Scottish Reformation. It had been endowed by the Earls of Carrick as well as the Earls of Fife, but over time lost its dependence on these and came to be controlled by the more locally based Home (or Hume) family, who eventually acquired the priory's lands as a free barony.