The Church of Saint Peter and Saint Paul is located in Roccalbegna’s main square. It has a Romanesque-Gothic façade with a staircase leading to the entrance – a splayed round portal, surmounted by a lunette, with a 16th century fresco in which titular saints are depicted, above which there is an eye rose window. The parish church has been documented since the late 13th century and, after the right side of the structure collapsed (as evidenced by the inclination of the portal architrave), the intervention of the Sienese painter Andrea Vanni was recorded in 1318. At the entrance, there is a Renaissance style marble stoup and, on the right, there is a banner of the anti-Jacobin movement which reads "Viva Maria". The large rectangular interior has a trussed roof that ends in a cross-shaped scarsella. On the main altar, there is a triptych by Ambrogio Lorenzetti depicting the Madonna and Child with Saint Peter and Saint Paul. On the right side, there is a 1476 fresco depicting the Madonna of Mercy, with Saint Sebastian and Saint Fabiano, and two contemporary frescoes from the church of the Madonna del Soccorso depicting Saint Giobbe and Saint Anthony the Abbot. The presbytery houses a wooden ciborium and a Piety dating back to the 16th century. On the left side, there is a monumental wooden altar, a 14th century polychrome Crucifixion, and a baptismal font in the shape of a small temple with the Sforza heraldic coat of arms.