The Church of the Holy Family (French: Eglise de la Sainte-Famille) is a Roman Catholic church located in the St. Clair County, Illinois city of Cahokia. Built in 1799 to replace a similar church built in 1699, it is a log building. Constructed of black walnut timbers in the traditional French Colonial "poteaux-sur-solle" (post-on-sill) vertical-log construction style, the Log Church is only one of five built in this style that still exist in North America. The church was declared a National Historic Landmark and added to the National Register of Historic Places in 1970. The building is located on First Street in Cahokia.