The concept of a 'green economy' has risen to prominence in recent years. However, little has been said about what actors could drive its widespread adoption at the global level. At present, global governance generally occurs in distinct policy domains or 'silos'; the global environment and the global economy are segregated. Within these domains, authority is highly fragmented among numerous institutions. However, two particular institutions have the broad scope and potentially the capacity to coordinate and steer green economy efforts: the United Nations Environment Programme (UNEP) and the Group of Twenty (G20). This article examines why some (including UNEP itself) have called for the G20 to take a greater role in steering the green economy and assesses the extent to which it has done so. The article concludes that the G20 was ineffective in promoting a 'green recovery' from the Global Financial Crisis (GFC) and has similarly failed to stimulate 'green growth'. Reform of both the G20 and UNEP could improve global policy on the green economy, but changes to the G20 would likely have a greater impact.