Canossa is a former castle of Matilda, Countess of Tuscany, situated in the foothills of the Apennines, about eighteen miles from Parma. One of the most dramatic moments in the history of the western church came when Emperor Henry IV knelt in the snow at Canossa in 1077 and begged Pope Gregory VII to lift the ban of excommunication. The pope had prohibited lay control over the placing of clergy in the church (particularly the investiture of bishops) and, by securing the forgiveness of Pope Gregory VII, the emperor was also securing the imperial power that had been jeopardized by his excommunication.

Canossa should not be confused with Canosa in Apulia in the south of Italy.