Denationalization is an emerging category for analysis that aims at capturing a specific set of components in today's major global transformations for which the typical terms in use – globalization, postnationalism, and transnationalism – are inadequate. These three terms all point to locations for change that lie outside the nation-state. The effort behind developing a fourth category – denationalization – arises out of an as yet small but growing body of research showing that critical components of today's major transformations actually take place inside the nation-state. The actual processes that constitute the transformation in this case have the effect of denationalizing what has historically been constructed as national. These processes are partial, often highly specialized and obscure. Further, they frequently continue to be coded, represented, and experienced in the vocabulary of the national, and hence can remain unrecognized and undetected. Thus this new category for analysis opens up a vast research and theorization agenda connected to global trends but focused on the nation-state. Sociology is particularly well situated to develop this agenda because its theories, methods, and data sets have to a large extent been shaped by the fact of nation-states. But while this new agenda can use and benefit from sociology's existing resources, it will require new interpretive instruments and framings.