Cistercian nuns are female members of the Cistercian Order, a religious order belonging to the Roman Catholic branch of the Catholic Church.

The Abbey of Santa María la Real de Las Huelgas is a monastery of Cistercian nuns located approximately 1.5 km west of the city of Burgos in Spain. The word huelgas, which usually refers to "labour strikes" in modern Spanish, refers in this case to land which had been left fallow. Historically, the monastery has been the site of many weddings of royal families, both foreign and Spanish, including that of Edward I of England to Eleanor of Castile in 1254, for example. The defensive tower of the abbey is also the birthplace of King Peter of Castile.