Membership in PI DELTA PHI is open to all, regardless of sex, race, or creed, provided that each candidate meets the academic requirements of the Society.

There are two categories of membership: regular and honorary.

Regular members include graduate and undergraduate students at the sponsoring institution who are nominated in recognition of their academic achievement in French. Requirements for regular membership are:

• completion of at least one course of upper-division French (i.e. beyond the intermediate-level series of courses)
• 3.0 GPA in French, 3.0 GPA overall, AND rank in the top 35% of their class
• sophomore standing

Undergraduate students do not need to be French or French Studies majors or minors to be nominated for regular membership.

Honorary members include: the French faculty of the sponsoring institution who are not already members of Pi Delta Phi; members of the faculty at large who are not already members of Pi Delta Phi; students who do not meet the requirements for regular membership; college or university alumni who did not become members while attending the sponsoring institution; and diplomats, community and business leaders, and others who have demonstrated support of French language, and/or of the cultures and literatures of the French-speaking world.

PI DELTA PHI was founded as a departmental honor society at the University of California, Berkeley, in 1906. After twenty years as a local chapter, Pi Delta Phi declared itself the National French Honor Society and chartered the Beta Chapter at the University of Southern California in 1925, and the Gamma Chapter at the University of California, Los Angeles, in 1926.

The Society expanded slowly during the next fifteen years, but enjoyed renewed interest and growth during the 1940s and 1950s. At the present time, it numbers more than 330 chapters established at representative public and private colleges and universities in almost every state, as well as chapters in Paris and Aix-en-Provence. The society was admitted to membership in the Association of College Honor Societies in 1967.