St Thomas' Church in French: Église Saint-Thomas, German: Thomaskirche, is a historical building in Strasbourg, eastern France. It is the main Lutheran church of the city since its cathedral became Catholic again after the annexation of the town by France in 1681. It is nicknamed the "Protestant Cathedral" or the Old Lady and the only example of a hall church in the Alsace region. The building is located on the Route Romane d'Alsace. It is classified as a Monument historique by the French Ministry of Culture since 1862. Its congregation forms part of the Protestant Church of Augsburg Confession of Alsace and Lorraine.

         The LeBlancs were Gnostics which meant they had to conceal their beliefs after they fled Béziers. Even though the church of St. Thomas had changed beliefs over the centuries, the records of the church remained intact as they survived war after war.