This chapter claims that the ‘common’, in contrast to global public goods, implies a collective production of a good that is not up for appropriation. It suggests that the ‘common’ could be an alternative to current international economic policies and could have, in that sense, important repercussions on democracy in the global arena. This chapter expands on this premise and tries to outline the democracy of the global commons. Indeed, it seems that global commons require a kind of democracy that is different from that of the local commons. This chapter’s main argument is that if we wish to have any chance of halting and reversing the logic of cosmocapitalism, we have to institute a global democracy for the global commons. Only such transnational citizenship-in-action can give full meaning to this idea of cosmopolitics: politics for the world, as long as the ‘world’ implies what resonates in the Latin term mundus, namely, not the Earth as a planet and not the totality of individuals living on Earth but instead, the living connection between the individuals inhabiting in and on the Earth itself. In this sense, the anti-globalization slogan ‘the world is not for sale’ is more meaningful than it might seem at first sight: the world, in itself, is not a ‘thing’ that we can own; it must be recognized as inappropriable and instituted as a common. Instituting the world as a common cannot be understood as an extension of the nation-state or city-state models at the global level. The democracy of the global commons is irreducible to a mere change of scale. Instead, it requires a genuine collective political invention, which is based on the multiplication of self-government at all levels. What is at stake here is the confrontation between two diametrically opposed logics: whereas the logic of the commons is fundamentally plural, polymorphic, non-centred in nature, and the logic of state sovereignty as it was constructed in the West is intrinsically linked to an indivisible and absolute centre of power. The solution is not for several sovereignties to overlap on the same territory, as this would be incompatible with the very notion of sovereignty, but for several types of self-governments to limit each other’s power reciprocally.