Ambiguous, yet proliferous, the concept of identity has taken an important place in the analysis of individuals, groups, and nations. The chapter introduces the literature on identify formation and identity politics, and clarifies why French political and sociological tradition has long rejected group identity as a notion that conflicts with the universalist understanding of the state. However, it also shows how recent studies have been influenced by the rich development of the literature on identity politics abroad and how France is now moving beyond the representative case of a universalist state. It discusses how the debate on identity has been shaped, with “national identity” on one hand, and the identity of the Other on the other hand, and how the question of identity has been crystallized on Islam. It demonstrates that French scholarship on identity is increasingly integrated into a larger scholarly community on transnational politics and practices.