Mildred Constantine Bettelheim (1913 – December 10, 2008) was an American curator who helped bring attention to the posters and other graphic design in the collection of the Museum of Modern Art in the 1950s and 1960s
Constantine (she used her maiden name professionally) was born in 1913 in Brooklyn, New York. She received bachelor's and master's degrees from New York University and attended the graduate school of the National Autonomous University of Mexico.
She worked for the College Art Association from 1931 to 1937 as an editorial assistant on the journal Parnassus. She met Rene d'Harnoncourt, her future boss as director of the Museum of Modern Art, while she was working at the Office of the Coordinator of Inter-American Affairs.
She traveled to Mexico in 1936 as part of the leftist Committee Against War and Fascism, where she developed an interest Latin and Central American political graphics. A Latin American poster collection she organized was shown at the Library of Congress and became part of the Metropolitan Museum of Art's permanent collection.
From 1943 through 1970, Constantine worked in the architecture and design department of the Museum of Modern Art, as associate curator and later as curatorial consultant, where she helped popularize collections that were hard to categorize or had been ignored, which she called "fugitive material". Her 1948 exhibition Polio Posters was the museum's first devoted to causes, and included works she commissioned to help spread awareness of various social issues.
She organized solo exhibitions for graphic and product designers including Alvin Lustig, Bruno Munari, Massimo Vignelli and Tadanori Yokoo that were described by The New York Times as "career-defining". Her broader-themed exhibitions in the applied and decorative arts included Olivetti: Design in Industry in 1952, Signs in the Street in 1954 and the 1962 exhibit of Lettering by Hand.