Pfäfers Abbey (German: Kloster Pfäfers), also known as St. Pirminsberg from its position on a mountain, was a Benedictine monastery in Pfäfers near Bad Ragaz , in the Canton of St. Gallen , Switzerland .

Situated at the junction of the Tamina and Rhine valleys, it flourished as a religious house and owner of lands and serfs, as well as assuming extraordinary importance as a political and cultural centre of the Chur –Raetian region.

According to the chronicles of Hermann of Reichenau, Pfäfers Abbey was founded from Reichenau Abbey in 731, as Monasterium Fabariense (Latin for bean field); the first monks came from Reichenau. The founding legend refers to the itinerant bishop Saint Pirmin, with the first documentary mention of the abbey in 762.