The Church of Saint-Sulpice is a Catholic church in Paris, France, on the east side of Place Saint-Sulpice, in the Latin Quarter of the 6th arrondissement. Only slightly smaller than Notre-Dame and Saint-Eustache, it is the third largest church in the city. It is dedicated to Sulpitius the Pious. Construction of the present building, the second on the site, began in 1646. During the 18th century, an elaborate gnomon, the Gnomon of Saint-Sulpice, was constructed in the church.