West Virginia State Capitol in the context of Charleston, West Virginia

Cass Gilbert (November 24, 1859 – May 17, 1934) was an American architect. An early proponent of skyscrapers, his works include the Woolworth Building, the United States Supreme Court building, the state capitols of Minnesota, Arkansas, and West Virginia, the Detroit Public Library, the Saint Louis Art Museum and Public Library. His public buildings in the Beaux Arts style reflect the optimistic American sense that the nation was heir to Greek democracy, Roman law and Renaissance humanism. Gilbert's achievements were recognized in his lifetime; he served as president of the American Institute of Architects in 1908–09.

Gilbert was a conservative who believed architecture should reflect historic traditions and the established social order. His design of the new Supreme Court building in 1935, with its classical lines and small size, contrasted sharply with the large federal buildings along the National Mall in Washington, D.C., which he disliked.