The E.W. Marland Mansion is a 43,561 square feet (4,046.9 m2) Mediterranean Revival-style mansion located in Ponca City, Oklahoma, United States. Built by oil baron and philanthropist Ernest Whitworth (E.W.) Marland, as a display of wealth at the peak of the 1920s oil boom, the house is one of the largest residences in the southwestern United States, and is known as the "Palace on the Prairie." It was designated a National Historic Landmark in 1973, and is now a museum open to the public.

Mediterranean Revival is an architectural style introduced in the United States, Canada, and certain other countries in the 19th century. It incorporated references from Spanish Renaissance, Spanish Colonial, Italian Renaissance, French Colonial, Beaux-Arts, Moorish architecture, and Venetian Gothic architecture.