Loccum Abbey (Kloster Loccum) is a former Cistercian monastery in the town of Rehburg-Loccum, Lower Saxony, near Steinhude Lake.
Originating as a foundation of Count Wilbrand of Hallermund, Loccum Abbey was settled from Volkenroda Abbey under the first abbot, Ekkehard, in 1163. An ancient account describes it as being "in loco horroris et vastæ solitudinis et prædonum et latronum commorationis" ("in a place of horror and a desert of solitude and a dwelling of thieves and brigands"); and adds that, after suffering much from want and from the barbarity of their neighbours, the monks in time brought the land into cultivation, and the people to the fear of God. Loccum very quickly grew wealthy and was under the direct protection of the Pope and the Emperor as an Imperial abbey (i.e., territorially independent).
In the 16th century in Protestant Reformation it became Lutheran. By 1700 the abbot of Loccum was permitted to marry and the Loccum Hof was built at Hanover to accommodate his spouse. The monastery retained its property and wealth until the agrarian reforms of the 19th century, when it was included in the territory of the Duchy of Braunschweig-Lüneburg, otherwise Hanover.
Since 1891 the monastery has also operated as a Protestant seminary and academy, a tradition going back to around the start of the 19th century. The title of "abbot" is retained, anomalously.
The community today generally consists of between four and eight members, most of whom are also in holy orders. In addition the Lutheran Bishop of Hanover and the Director of Studies of the seminary are members ex officio. The abbot and prior are chosen from among the members.
The abbey is known for its extremely well preserved monastic buildings from the late Romanesque period with church, cloister and associated rooms, chapter-house, sacristy, dormitory, refectory, library and lay-brothers' wing, as well as the various service buildings. The buildings as a whole are considered of equal architectural worth with Maulbronn Abbey and Bebenhausen Abbey. The monastery's ponds and woods also throw an interesting light on the abbey's medieval economy.