The Joseph Raphael De Lamar House is a mansion located at 233 Madison Avenue at the corner of 37th Street in the Murray Hill neighborhood of Manhattan, New York City. It was built in 1902-05 and was designed by C. P. H. Gilbert in the Beaux-Arts style. The De Lamar Mansion marked a stark departure from Gilbert's traditional style of French Gothic architecture and was instead robustly Beaux-Arts, heavy with rusticated stonework, balconies and a colossal mansard roof.