This chapter presents the importance of groundwater in the development of coastal cities in Africa, and how it contributes to their socio-economic growth, as well as the threats they face. Based on historical, economic, and sociological factors, the major role of groundwater in the development of coastal cities in Africa has been demonstrated and the city of Lomé in Togo is an example. The presence of coastal aquifers favoured the establishment of large African cities on the coast during colonisation. In addition, coastal aquifers contributed to their urban and socio-economic development (water access for vulnerable populations, industry, job creation, etc.). This development has in turn led to problems of overexploitation and pollution of groundwater, which are exacerbated by the effects of climate change. Furthermore, this poses new challenges for the sustainable management of groundwater across the continent. This study highlights the contribution of groundwater in building the African continent as we know it today. In addition, it draws attention to the need to develop new and effective approaches to preserve the resource.