This report offers guidance on how to prepare regions and cities for the transition towards a climate-neutral and circular economy by 2050 and is directed to all policymakers seeking to identify and implement concrete and ambitious transition pathways. It describes how cities, regions, and rural areas can manage the transition in a range of policy domains, including energy supply, conversion, and use, the transformation of mobility systems, and land use practices. It takes stock of discussions between academic and policy experts emanating from a series of high-level expert workshops organised in 2019 by the OECD and the European Commission. Bringing together frontier thinking and practical examples regarding the transition to a climate-neutral economy, the transition to a circular economy, the transition in cities, the transition in rural areas, and financing and scale-up of transition action, this report identifies cross-cutting lessons to support urban, regional, and rural decision makers in managing trade-offs and in promoting, facilitating and enabling environmental and energy transitions.