The Saint-Léonard church takes its name from the hermit Saint Léonard de Vandoeuvre. The latter, born at the end of the 5th century, left his family to serve God and settled in a place called Vandoeuvre, in Saint-Léonard-des-Bois, where he lived in austerity for several years. Joined by a few disciples, he built a monastery protected by King Clotaire. The relics of Saint Leonard, who died in 570, were transported in 868 to Corbigny by the monks of Vandoeuvre to preserve them from the Normans. Part of these was undoubtedly returned around 1025 thanks to the second lord of Alençon, William I, and deposited in an old chapel dedicated to Saint Martin located on the site of the current Saint-Léonard church. This saint is often invoked to cure deafness.
A first Saint-Léonard church, attested between 1160 and 1182, was probably built very close to the Saint-Martin oratory. This disappeared around the middle of the 13th century in forgotten circumstances, but parish life remained concentrated in the chapel until the end of the 15th century.
It is on the latter that the current church was built, in tertiary ogival style and flamboyant Gothic interior, by Duke René d'Alençon and his wife Marguerite de Lorraine. Most of the work took place from 1490 to 1505 and it was this same year that the building was placed under the name of Saint Leonard de Noblac, a character then more popular than Saint Leonard de Vandoeuvre.
On the stained glass windows of one of the eleven side chapels, which was for a certain time dedicated to Louis IX, ancestor of the counts and dukes of Alençon, and on the walls, appeared the coats of arms of the houses of Alençon and Lorraine, today now disappeared. It was in this chapel that the duchess and the duke attended services and in which a fireplace was built for them which no longer exists. After René's death, his heart is placed in a lead box, itself in the shape of a heart, covered with a stone. When around 1510, René's heart was transferred to the church of Saint-François de Mortagne, the empty box was left in his vault. In 1776, the stone, which also bears the imprint of a heart, was removed, then put back in its place, and this imprint, erased by the friction of the feet, no longer exists except in memory. In 1562, the church was pillaged by Protestants. At Easter 1645, Hertré's granite vault collapsed. Replaced by a simple plaster cradle, it was not until 1836 that a new Gothic style vault was built. The main door was built in 1663 and the clock was installed in 1727. Until 1789, this church depended on Notre-Dame and did not have a baptismal font. The carved wooden altar and pulpit, two side consoles and some mostly modern stained glass windows, deserve the tourist's attention. The Saint-Léonard church, restored in the 17th-18th centuries, then completely refurbished in the 19th century by the architect Isidore Dédaux, is classified among the historic monuments.