Urbanisation is one of the key mega-trends that will shape the economic, social and political future of sub-Saharan Africa in the decades to come. It is closely interlinked with demographic and economic trends, and it is likely to increasingly affect politics in the region too. Historically, cities are engines of economic growth, innovation and productivity. Yet in sub-Saharan Africa rapid population growth is happening in the context of slow structural economic transformation, pervasive poverty, sharp inequalities and widespread socioeconomic and spatial exclusion, and environmental degradation. These conditions severely compromise the prospects for sustainable urban futures. In the best case, the urban transition will help surmount some of these structural hurdles. In the worst case, it will compound them. Most likely, the future will be a mixed picture reflecting the diversity of African countries, in particular their demographic and economic baselines as well as the quality of (both national and urban) governance.