This article traces the origins and implementation of a research program aiming to draw up an inventory of current field work on minority religious groups in France (excluding overseas collectives). At a time when the religious diversity of France is receiving more and more attention in the media, the project presented in this article has the threefold aim to provide a complete, precise, and objective presentation of this varied landscape, down to its most discreet expressions. Drawing on the competence of many specialists, the project makes it possible to question the definition of these groups, and to discuss the importance of religion in contemporary France and debate the issues of religious diversity and interreligious confrontation. This presentation of France’s religious landscape fills a void in information and scholarship. It also allows us to come to a better understanding of recent religious developments in France, most notably perhaps the change in the status of Catholicism.