The concept of “Global Citizenship” is enjoying increased currency in the public and academic domains. Conventionally associated with cosmopolitan political theory, it has moved into the public domain, marshaled by elite actors, international institutions, policy makers, nongovernmental organizations, and ordinary people. At the same time, scholarship on Global Citizenship has increased in volume in several domains (International Law, Political Theory, Citizenship Studies, Education, and Global Business), with the most substantial growth areas in Education and Political Science, specifically in International Relations and Political Theory. The public use of the concept is significant in light of what many scholars regard as a breakdown and reconfiguration of national citizenship in both theory and practice. The rise in its use is indicative of a more general change in the discourse on citizenship. It has become commonplace to offer globalization as a cause for these changes, citing increases in regular and irregular migration, economic and political dispossession owing to insertion in the global economy, the ceding of sovereignty to global governance, the pressure on policy caused by financial flows, and cross-border information-sharing and political mobilization made possible by information communications technologies (ICTs), insecurities caused by environmental degradation, political fragmentation, and inequality as key drivers of change. Global Citizenship is thus one among a string of adjectives attempting to characterize and conceptualize a transformative connection between globalization, political subjectivity, and affiliation. It is endorsed by elite global actors and the subject of an educational reform movement. Some scholarship observes empirical evidence of Global Citizenship, understood as active, socially and globally responsible political participation which contributes to global democracy, within global institutions, elites, and the marginalized themselves. Arguments for or against a cosmopolitan sensibility in political theory have been superseded by both the technological capability to make global personal legal recognition a possibility, and by the widespread endorsement of Global Citizenship among the Global Education Policy regime. In educational scholarship Global Citizenship is regarded as a form of contemporary political being that needs to be socially engineered to facilitate the spread of global democracy or the emergence of new political arrangements. Its increasing currency among a diverse range of actors has prompted a variety of attempts either to codify or to study the variety of usages in situ. As such the use of Global Citizenship speaks to a central methodological problem in the social sciences: how to fix key conceptual variables when the same concepts are a key aspect of the behavior of the actors being studied? As a concept, Global Citizenship is also intimately associated with other concepts and theoretical traditions, and is among the variety of terms used in recent years to try to reconceptualize changes it the international system. Theoretically it has complex connections to cosmopolitanism, liberalism, and republicanism; empirically it is the object of descriptive and normative scholarship. In the latter domain, two central cleavages repeat: the first is between those who see Global Citizenship as the redress for global injustices and the extension of global democracy, and those who see it as irredeemably capitalist and imperial; the second is between those who see evidence for Global Citizenship in the actions and behavior of a wide range of actors, and those who seek to socially engineer Global Citizenship through educational reform.