Versailles Cathedral (Cathédrale Saint-Louis de Versailles) is a Roman Catholic cathedral, and national monument of France, in Versailles.
It is the seat of the Bishop of Versailles, created as a constitutional bishopric in 1790 and confirmed by the Concordat of 1801.
It was built as the parish church of Saint Louis before becoming the cathedral of the new diocese. The building is of the mid-18th century: the first stone was laid, by Louis XV, on 12 June 1743 and the church was consecrated on 24 August 17chosen, and used, as the cathedral by the post-Revolutionary bishop, who preferred it to the church of Notre-Dame in Versailles, which had been the choice of the preceding constitutional bishop. Its consecration as a cathedral was however severely delayed, and was not performed until 1843, by the diocese's third bishop, Louis-Marie-Edmond Blanquart de Bailleul.