The Church of Santa Maria Maggiore is one of the most significant religious buildings in Labro, in the province and diocese of Rieti. An integral part of the pastoral area of Montepiano Reatino, it is first mentioned in 1398. Its origin is particularly interesting: it was derived from the transformation of the De' Nobili family's palace of arms.
Toward the end of the 15th century, following the murder of a priest by Giovanni de' Novili, the latter's castle was demolished by order of Pope Sixtus IV. A chapel dedicated to the Blessed Virgin of the Rosary was built in its place. On February 11, 1508, the church became a collegiate church at the behest of Cardinal Giovanni Colonna, apostolic administrator of Rieti.
In the 17th century, the building underwent several upgrades, especially in the presbytery. In the 1970s, the church was updated according to post-conciliar standards, and in 2015 it was restored and consolidated.
The façade of the church, made of stone and with a horizontal crowning, has two entrances: the main one, topped by a small rose window, and a secondary entrance on the right, leading to the side aisle. Adjacent to the church is a square-based bell tower with two registers and single-light openings, topped by a hipped roof.
The interior of the church is divided by pillars into two naves. The nave, divided into four bays and covered by cross vaults, has two chapels on the left side. The side aisle, located on the right side and also cross-vaulted, is divided into six bays. At the end of the hall is the chancel, raised a few steps and enclosed by a flat wall.