This chapter provides an historically informed, critical analysis of the main principles, modalities and models of South-South Cooperation (SSC). The narrative of SSC is first and foremost a political project aimed at fostering Southern solidarity and establishing a distinction between North-South and South-South relations. As Southern economies have grown in size and ambition, SSC has become a more well-defined and distinct framework for fostering mutual economic growth. But differing rates of economic growth combined with increased economic interdependency have also revealed crucial points of divergence and conflict within the global South whereby the narrative of SSC thus now also acts as a legitimating device to obscure these differences within the global South itself. Drawing on examples from Asian-African economic cooperation and the G77’s participation in global climate negotiations, this chapter argues that SSC creates new opportunities for Southern economies while highlighting the fault lines and contradictions of a Southern project as individual countries pursue their own interests and alliances. The chapter thus analyses SSC as a political project, an economic framework and a symbolic regime.