Rheinau Abbey (Kloster Rheinau) was a Benedictine monastery in Rheinau in the Canton of Zürich, Switzerland, founded in about 778 and suppressed in 1862. It is located on an island in the Rhine. In 1867, a cantonal hospital and nursing home were set up in the abbey buildings. The later cantonal psychiatric clinic that developed here was closed in 2000, since when the buildings have stood empty.