Église priorale Sainte-Opportune de Moussy-le-Neuf, Ruined church in Moussy-le-Neuf, France.

The Église priorale Sainte-Opportune is a ruined church in Moussy-le-Neuf in Seine-et-Marne where the choir wall and lower sections of the northern side still stand visible among vegetation. The remains now form part of the adjoining farm complex where agricultural buildings occupy the surrounding area.

A sanctuary was mentioned in 876, built after the relics of Saint Opportune, first kept in the house of a man named Gozlin, drew pilgrims. In 879 a captain of King Boson of Provence was prevented from ravaging the church and took the clergy of Moussy under his protection. The church was rebuilt around 1220, and the relics were later moved to Notre-Dame de Paris and then to the Paris church of Sainte-Opportune. After the Revolution the priory passed to Jean-Baptiste Bernadotte and the church became a barn.

The church was dedicated to Saint Opportune, whose relics drew pilgrims; a pilgrimage was still held here on 22 April and lasted nine days until recently. In the 19th century the building still held a woman's tomb carved in Gothic letters and the tomb of Prior Achilles le Petit, who died on 29 July 1584, with an inscription recalling his repairs.

The ruins sit on private farmland along Rue Jeanne d'Arc and are partly visible from the road without entering the property. Getting closer to examine the structure requires permission from the property owners, so respect the private boundaries.

The 19th-century account records relics kept here: those of the martyrs Can, Cantien and Cantienne, and a jawbone of Chrodegang de Séez. It also noted the tomb of prior Achilles le Petit, who died on 29 July 1584, with an inscription recalling his repairs. Only the chevet wall and the lower north side of the nave remain today.