The signing of the African Continental Free Trade Agreement (AfCFTA) has stimulated a lot of trade potential in Africa that could see the continent significantly improving its intra-trade levels, thereby boosting the economic welfare of Africans. In light of food security sustainability in the Southern African Development Community (SADC) region, this paper employed the World Integrated Trade Solution, Software for Market Analysis and Restrictions on Trade (WITS-SMART) simulation model to assess the potential effects of the AfCFTA on trade in cereals. Cereals have been regarded as the most critical component of food security. The model indicated trading partners for each of the 15 SADC countries, their level of trade creation, trade diversion, consumer surplus, welfare and revenue effects of any regional trade agreement. The results indicated that the AfCFTA will only lead to positive outcomes in four (Angola, the Democratic Republic of Congo, Madagascar and Namibia) of the fifteen SADC countries, with the rest remaining unchanged. In general, previously closed economies, that is, economies which were not part of a free trade agreement (FTA) or a deeper arrangement will stand to gain more than open economies because they are already opened up at the free trade level, which is equivalent to the AfCFTA. Thus, as far as cereals and food security is concerned, the AfCFTA will add minimal value. However, the overall value gains are likely to be greater when all food categories are included in the simulations. In general, the study recommends that African countries should deepen their integration levels to perhaps common markets where production factors, that is, labour and capital, become mobile. This will have multiplier effects in improving continental food security sustainability from a trade perspective.