The Theodore A. Pappas House in St. Louis, Missouri, is a historic Frank Lloyd Wright design and the only Usonian Automatic in Missouri, as well as one of just two Wright houses in the city. Designed between 1955 and 1959 for Theodore and Bette Pappas, it was built by the couple with day laborers from 1960 to 1964. The four-bedroom house uses a modular system of pretinted concrete blocks, steel rods, and grout to form its entire structure, including the roof. Listed on the National Register of Historic Places in 1979, it later passed to the Frank Lloyd Wright Revival Initiative and opened for public tours in 2021.