The preliminary findings from the report, Rapid Urbanization in Small and Medium-sized Cities: Implications for climate and energy, seek to broaden the understanding of rapid urbanization and its effects on these often overlooked cities. As small and medium-sized cities play an increasingly critical role in future urban growth, there is an urgent and strategic need to analyze their patterns of urbanization, especially in relation to climate and energy vulnerabilities. Five new typologies of rapidly urbanizing cities are introduced, exploring their regional variations, differing environmental impacts, as well as critical opportunities and challenges. The report’s emerging findings and recommendations ultimately aim to inform future GCoM alliance activities, deepening and scaling engagement across rapidly urbanizing cities through knowledge, technical support, and partnerships.