While the concept of global citizenship has a pedigree dating back more than 2000 years, as well as many current advocates and interpreters, scholarly critics tend to dismiss it as simply incoherent. How, they ask, can it be possible to practice global citizenship in the absence of some global state? This chapter argues that, although the full formal trappings of citizenship are not likely to emerge anytime soon at the global level, individuals can make important contributions toward realizing its substance there. In assuming duties to promote comprehensive rights protections for others who do not share their state citizenship, and promoting the sort of supra-state institutional transformation that could more reliably secure such protections, they can enact some key aspects of global citizenship. Further, such an institutionally developmental approach to global citizenship is shown to be less distinct than claimed from domestic conceptions, which define citizenship partly in terms of ideals and practices that are acknowledged to need further development.