Global food demand is expected to increase considerably, reflecting the predicted increase in global population. In sub-Saharan Africa (SSA), where it is reported that one in four people remain malnourished and the population is predicted to double by 2050, achieving food security in terms of quantity and quality is an immense challenge. Conversely, in SSA, agricultural production potential has not been fully realized owing to poor soil fertility and adverse environmental conditions. Moreover, these regions are vulnerable to climate change and infectious diseases. The second goal of the 17 sustainable development goals calls on all nations to achieve “Zero Hunger.” Through joint research, the Food Security in Africa project by the Japan International Research Center for Agricultural Sciences has promoted sustainable technology development to improve food security in SSA in three focus areas: enhanced rice production, utilization of regional crops, and effective resource utilization under integrated crop–livestock systems. In this review, we introduce the technical challenges and problems of agriculture in SSA, explain the project’s efforts to address them, and discuss future prospects. We believe that all diverse stakeholders involved need to continue to work together to contribute to the maintenance of food and nutrient supply in SSA.