The rising profile of the G20 in the aftermath of the Global Financial Crisis has led to various forms of concern about the legitimacy of this forum. While debates about the legitimacy of the G20 are important and ongoing, they overlook the important observation that the G20 is also attempting to perform a key role in legitimating global capitalism. This role of legitimating global capitalism emphasises the importance of the G20 to act, and be seen to act, to normalise global capitalism, to strengthen global economic governance, and also facilitate a political consensus with regard to key policy issues. This essay critically examines the role that the G20 plays in legitimating global capitalism and contends that the G20 is not just a technical forum of international policy-making but also a political forum for creating and performing visible responses to problems which are seen to be socially responsive.