Resource extraction and consumption is projected to double by 2060. However, today only 8.6% of raw materials extracted are put back into circulation, which worsens pressure on ecosystems, intensifies pollution and waste issues, and accelerates climate change. The transition from a linear to a circular economy opens a pathway for a green, more sustainable and resource-conscious future. To this end, we recommend that the Group of Twenty (G20): (1) acknowledges the value of circular cities for the G20, (2) embeds circularity into multinational supply chains, (3) boosts circularity through digitalisation and (4) implements a just transition through context-sensitive, localised approaches.