The primary aims of this work are to explore some of the most salient emerging theories of global justice and defend a particular approach to the matter—an approach that the author presents in the form of one single demand: to ensure that everybody has enough to lead a dignified life. This book brings to light some of the most prominent theories of social justice that converge into the idea of global social justice as captured in this single demand, i.e., in the demand to reach what the author calls the sufficiency threshold. This work defends a moderate sufficientarian perspective that rejects strict egalitarianism and dogmatic anti-egalitarianism. The author advocates the view that social justice is not exhausted in nation-state systems and, at the same time, argues that we should not think of global social justice as (domestic) social justice writ large. Empirically based claims from other academic fields in the social sciences (e.g. sociology, history, political theory, development theories) play a relevant role in the proposed task of making sense of global social justice.