The discussion surrounding how countries in sub-Saharan Africa can reap the benefits of a demographic dividend needs to pay closer attention to the effects of internal and international migration flows. Surprisingly little attention has been paid to the ways in which migration alters the relative size of the working age population, the ratio of children to the total population, and the education level of a population, all of which are key variables in the discussion of the demographic dividend. This chapter aims to address this gap in the literature by drawing on two new datasets on internal and international migration flows as well as an innovative visualization of migration systems. The data suggests that, during the period 1990–2010, the spatial patterns of migration flows in sub-Saharan Africa were distinctive from those observed in the more developed world. Economic factors seem to play a less important role in shaping migration compared to violent conflict and political unrest. The results point to three clusters of countries between which migration flows are concentrated, underlining the importance of the regionalization of migration within sub-Saharan Africa.Migration, urbanization and the growth of slums have been key features in the search for pathways to address Africa’s development challenges relating to poverty, health, environmental quality and social welfare provision. Considerable concerns around these issues have raised intricate social policy challenges across the region. This chapter provides an overview of the state of migration, urbanization and slums in the region. The chapter highlights associated challenges that will inform policy and program responses in order to achieve development goals and aspiration in the sub-Saharan Africa region.