Cooper Hewitt, Smithsonian Design Museum is a design museum at the Andrew Carnegie Mansion in Manhattan, New York City, along the Upper East Side's Museum Mile. It is one of 19 Smithsonian Institution museums and one of three Smithsonian facilities located in New York City, along with the National Museum of the American Indian's George Gustav Heye Center in Bowling Green and the Archives of American Art New York Research Center in the Flatiron District. Unlike other Smithsonian museums, Cooper Hewitt charges an admissions fee. It is the only museum in the United States devoted to historical and contemporary design. Its collections and exhibitions explore design aesthetic and creativity from throughout the United States' history.

The Andrew Carnegie Mansion is a historic house and a museum building at 2 East 91st Street, along the east side of Fifth Avenue, on the Upper East Side of Manhattan in New York City. The three-and-a-half story, brick and stone mansion was designed by Babb, Cook & Willard in the Georgian Revival style. Completed in 1902 for the industrialist Andrew Carnegie, his wife Louise, and their only child Margaret, it served as the family's residence until 1946. Since 1976, the house has been occupied by the Cooper-Hewitt Museum, part of the Smithsonian Institution. The mansion is internally connected to two townhouses at 9 East 90th Street and 11 East 90th Street, both of which are part of the Cooper-Hewitt.