Twentieth Century Theatre is a registered historic building in Cincinnati, Ohio, listed in the National Register on August 26, 1993.

Twentieth-century theatre describes a period of great change within the theatrical culture of the 20th century, mainly in Europe and North America. There was a widespread challenge to long established rules surrounding theatrical representation; resulting in the development of many new forms of theatre, including modernism, Expressionism, Impressionism. political theatre and other forms of Experimental theatre, as well as the continuing development of already established theatrical forms like naturalism and realism.