Unity Temple is a Unitarian Universalist church in Oak Park, Illinois, and the home of the Unity Temple Unitarian Universalist Congregation. It was designed by the American architect Frank Lloyd Wright, who was a member, and built between 1905 and 1908. Unity Temple is considered to be one of Wright's most important structures dating from the first decade of the twentieth century. Because of its consolidation of aesthetic intent and structure through use of a single material, reinforced concrete, Unity Temple is considered by many architects to be the first modern building in the world. This idea became of central importance to the modern architects who followed Wright, such as Mies Van Der Rohe, and even the post-modernists, such as Frank Gehry.
The building has been a United States National Historic Landmark since 1971 and was chosen in a 1991 poll in the magazine, Architectural Record as one of the 100 most significant buildings in the United States of the previous 100 years (Unity Temple was #6). Additionally, Unity Temple was chosen by the American Institute of Architects as one of 17 buildings by Frank Lloyd Wright that should be retained as his architectural contribution to American culture.