As the Paris Agreement formalized a climate regime transition towards a more polycentric approach, non-state agents have been perceived as influential actors in global climate governance. Observing the implementation of climate targets by regional governments in federal or decentralized systems, the dynamics of climate leadership are also being defined by these actors. While recent literature recognized the emergence of such dynamics in increasingly polycentric structures, the consideration of regional action in the domain of climate leadership demonstrates a shortage of conceptual and empirical studies. Reviewing the existent references on polycentric governance, but also climate leadership, this paper is guided by two goals: (i) to problematize and acknowledge the literature gap on the phenomenon of regional leadership in global climate governance; and (ii) justify the relevance and need of developing such study.