The debates about the legitimacy of the Group of Twenty (G20) present possibilities for the G20 to recalibrate its processes and policy ideas. The argument about the important relationship between the G20’s power and legitimacy has been guided by a critical constructivist approach that focuses upon the various forms of communication, ideas and practices involved in the G20 process. The G20’s meetings of leaders are supported by various transgovernmental and transnational networks. Critical constructivism’s capacity to help understand the G20 rests on its focus on communication, ideas and change. The idea of reinforcing global governance identifies that critical constructivism is a pragmatic account that seeks to engage with global politics to help identify opportunities that address global problems facing the world’s population. The role of the G20 as a site for global policy-making that will promote a liberal order is questionable.