Saint John's Abbey is a Benedictine monastery in Collegeville Township, Minnesota, United States, affiliated with the American-Cassinese Congregation. The abbey was established following the arrival in the area of monks from Saint Vincent Archabbey in Pennsylvania in 1856. Saint John's is one of the largest Benedictine abbeys in the Western Hemisphere, with 110 professed monks. The Right Reverend Fr. John Klassen, OSB, serves as the tenth abbot.