The parish church of Roussillon was established at the end of the 11th century in the upper part of the village inside the fortifications and opposite the castle. Redesigned over the centuries and rebuilt in freestone, it is dedicated to Saint Michael the Archangel, the patron paint of Roussillon. Its current facade dates from the 17th century, and its baptismal fonts designed by the Roussillonnais sculptor Alexis Poitevin at the end of the 18th century are now listed. The choir, the statue of Saint Michael, the Christ on the Cross, and Saint-Michel Chapel date from the same period.