St Mary's Abbey, Melrose is a partly ruined monastery of the Cistercian order in Melrose, Roxburghshire, in the Scottish Borders. It was founded in 1136 by Cistercian monks at the request of King David I of Scotland and was the chief house of that order in the country until the Reformation. It was headed by the abbot or commendator of Melrose. Today the abbey is maintained by Historic Environment Scotland as a scheduled monument.
The east end of the abbey was completed in 1146. Other buildings in the complex were added over the next 50 years. The abbey was built in the Gothic manner and in the form of a St. John's Cross. A considerable portion of the abbey is now in ruins. A structure dating from 1590 is maintained as a museum open to the public.
Alexander II and other Scottish kings and nobles are buried at the abbey. A lead container believed to hold the embalmed heart of Robert the Bruce was found in 1921 below the Chapter House site; it was found again in a 1998 excavation and documented in records of his death. The rest of his body is buried in Dunfermline Abbey.