Like many other oceanic islands around the globe, environmental conditions, social circumstances and forces of globalization combine to challenge the sustainability of the Galapagos Archipelago of Ecuador. This paper describes a food-supply system in Galapagos that is mainly controlled by population growth, weak local agriculture, imports from mainland Ecuador and the influence of a growing tourism industry. We use system dynamics (SD) as a modeling technique in this paper to identify the main driving forces operating on the Galapagos food system to create a series of future scenarios and to examine the subsequent implications across the supply system structures. We model the supply side of the food system using secondary data collected from governmental and non-governmental sources. We find that the consumption profile of the local inhabitants of the Galapagos is on average higher than consumption in the Ecuadorian mainland. This fact, plus rapid growth of the local population fueled by the tourism industry, has created a decrease in per capita local food production and an increase on food import dependence that now, challenges the sustainability of the archipelago. Imports are the largest source of food in the archipelago. Approximately 75% of the agricultural food supply was transported from the mainland in 2017. Our model projects that this fraction will increase to 95% by 2037 with no changes in food policy. Moreover, any plan to increase tourism arrivals must be accompanied by a plan to address the subsistence needs of the new population that the tourism industry attracts. Policies to promote local agricultural growth should be central to the development strategy implemented in the Galapagos.