Frienisberg Abbey is a former Cistercian religious house in the Swiss municipality of Seedorf in the Canton of Bern .

In 1131 Count Udelhard of Saugern granted his land at Frienisberg to the Cistercian Lützel Abbey. In 1138, the Lützel Abbey sent settlers to Frienisberg to found a new abbey. The new abbey remained small and struggled until the first half of the 13th century, when a number of donations allowed it to expand. In 1233 it owned land in Frienisberg, Allenwil, Ried, Tedlingen, Niederwiler, Werd, Gäserz bei Ins and Montils bei Nugerol. At its peak, about 300 farmers worked 5,000 Juchart (a measurement of acreage related to the Roman Jugerum, 1 Juchart was .36 hectares [0.89 acres] for a total of 1,800 hectares [4,400 acres]) in 45 villages west of Bern.