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Pi Delta Phi is the National French Honor Society for undergraduate and graduate students at accredited public and private colleges and universities in the United States. The highest academic honor in the field of French and the oldest academic honor society for a modern foreign language in the United States, Pi Delta Phi was founded as a departmental honor society at the University of California at Berkeley in 1906. The Society was nationalized when the Beta Chapter was established at the University of Southern California in 1925. The society was admitted to membership in the Association of College Honor Societies () in 1967, and was officially endorsed by the  as the only collegiate French honor society in 1949. There are currently more than 370  of the Society in the United States and two representative chapters at the American Universities in Paris and Aix-en-Provence in France.

The purpose of the Society is to recognize outstanding scholarship in the French language and Francophone literatures, to increase the knowledge and appreciation of Americans for the cultural contributions of the French-speaking world, and to stimulate and to encourage French and francophone cultural activities.