Roskilde Abbey or Our Lady's Abbey, Roskilde (Roskilde Kloster or Vor Frue Kloster) was a monastery of nuns dedicated to Saint Mary the Virgin in Roskilde in Denmark. It was founded in the early 12th century for Benedictine nuns, but in 1177 became part of the Cistercian reform movement.
It was chiefly known for the tomb of Saint Margrethe or Margaret of Ølsemagle or of Højelse (both names of places near Køge), who, although murdered by her husband, had been wrongly buried as a suicide on the beach at Køge. After miracles were declared to have happened round her grave, her remains were moved to the Abbey Church, the Vor Frue church, in 1176 by Absalon of Lund, Bishop of Roskilde, a kinsman of Margrethe; he arranged for the construction of a suitable shrine in the church, and transferred the nunnery to the Cistercians in the following year. Despite Absalon's best efforts, and also despite the local veneration, Margrethe was never formally canonised. The shrine was nevertheless later declared a place of pilgrimage by the Pope, and the nuns were allotted one third of the income generated by it. Despite all efforts, however, the center of the cultus remained the small chapel built near Margrethe's original grave on the beach.
The abbey was suppressed in 1536 during the Protestant Reformation in Denmark.
Coordinates: 55°38′19″N 12°04′57″E / 55.6385°N 12.0824°E