This paper presents estimates of the geographical and technical potentials for solar electricity generation in rural areas of West Africa (ECOWAS region). The study is performed by application of Geographic Information Systems (GIS) and Multi-Criteria Decision Making (MCDM) methods. We study both opportunities for large- scale grid-connected solar systems (photovoltaic, and concentrated solar power technologies), and for off-grid solar systems (photovoltaic). Locations are evaluated according to their suitability for solar systems' deployment according to topographical, legal, and social constraints, as well as factors that could facilitate or impede solar generation development. The study is conducted on a regional scale. The results can be used for identification of potential areas of interest for solar generation deployment, and as a support for integration between electricity grid expansion and off-grid electrification policies.