In this chapter, I claim that the central question of global justice in education is which – if any – educational inequalities between citizens and non-citizens in a democratic state are morally legitimate, and which inequalities between them contradict the normative foundations of democratic education. By trying to find a convincing answer to this question, I first briefly recapitulate the controversy between the cosmopolitan and the state-nationalist approaches to it. Then I elaborate on the question, whether special obligations to a privileged treatment of cocitizens over noncitizens apply to institutionalized education. I make the claim that the answer to that question depends on how we understand education – whether we spell it out as a traditionalist-authoritarian, or as democratic social practice. I argue that democratic education necessarily implies moral universalism. It requires not only the recognition of the equal moral status of all students, but also the inclusion of their individual experiences, worldviews, and ideals, regardless of their nationalities, or ethnic or cultural backgrounds, in an open and “diversity-friendly” ethical discourse that should be established in every classroom. I conclude that since democratic education is necessarily cosmopolitan in its essence, democratic educational institutions should be supranationally orientated.