St. Peter's Church is located beneath Deutschhaus Mainz in the northwest of the historical center of Mainz, Germany. It is one of the most important rococo buildings in Mainz. Originally it was a collegiate church monastery of ″St. Peter before the walls″, which had existed since the 10th century and is dedicated to the apostle Peter as patron. Today it serves as a parish church for the parish of St. Peter / St. Emmeran.