The church of Saint Denis, in Cessy, was given to the Benedictine order in 1091, by Guy, bishop of Geneva. The choir was the former chapel of the monastery, and the nave was built later.
In the 15th century, two sidechapels were built. One was dedicated to Saint Theodule, and was built by the Forestier family. The chapel of Our Lady was built by the Tavernier family. For a few decades, the protestants took over and the church became a protestant temple. The catholic religion was re-established in 1609.
In 1754, a fire destroyed most of the nave, which has been only temporarily rebuilt afterwards. In 1853, the bell tower and the facades were renovated. Louis Quinat was the entrepreneur, and he hired the architect Claude Regard. The family Rouph de Varicourt gave 1500 francs to the municipality to help for the reconstruction. In 1973, thanks to the priest Georges Guiffray, important renovations took place in the choir. The walls and the vault were cleared so that the stones became visible. All the lights were changed, a heating system was installed, and the floor was covered with red bricks. Young people from Cessy helped a lot for the renovation, through the assistance of the Sacred Art Commission, and guided by the Barberot company from Bourg-en-Bresse. In 1975, the wooden floor was replaced by a stone floor, and the furniture was changed.