Irsee is a village and municipality in the district of Ostallgäu in Bavaria in Germany.

The centre of the village is dominated by a monastery (Klosterbau), dedicated to the Virgin Mary, was founded in 1186 by Margrave Henry of Ronsberg to house a community that had grown up around a local hermit. It came close to collapse in the 14th century, when the community was reduced to a single monk, and was saved only by the intervention in 1373 of Anna von Ellerbach, the second founder, sister of the Bishop of Augsburg, and her appointee, abbot Conrad III, known for his extreme frugality. After severe losses during both the German Peasants' War in 1525 and the Thirty Years' War in the 17th century, including on both occasions the destruction of the library and on the second occasion of the archives, the abbey was finally able to put itself back on a stable footing in the later 17th century, and at length in 1694 was granted Imperial immediacy, becoming an Imperial abbey (German Reichsabtei). The monastery was dissolved in the German mediatization of 1802, when its lands became a part of Bavaria. The greater part of the library was moved to Metten Abbey.