The tensions between democracy and justice have long preoccupied political theorists. Institutions that are procedurally democratic do not necessarily make substantively just decisions. Democratizing Global Justice shows that democracy and justice can be mutually reinforcing in global governance - a domain where both are conspicuously lacking - and indeed that global justice requires global democratization. This novel reconceptualization of the problematic relationship between global democracy and global justice emphasises the role of inclusive deliberative processes. These processes can empower the agents necessary to determine what justice should mean and how it should be implemented in any given context. Key agents include citizens and the global poor; and not just the states but also international organizations and advocacy groups active in global governance. The argument is informed by and applied to the decision process leading to adoption of the Sustainable Development Goals, and climate governance inasmuch as it takes on questions of climate justice.