Fuel is a little considered part of the ancient economy. The production and consumption of food constituted one of the major uses of fuel in the Greco-Roman world. It was required on an industrial scale in bakeries, temples and probably bars, but it was also required daily in people’s homes mostly for cooking food (in the kitchen, and in the triclinium), and also for sacrificing to the Lares. Wood and wood charcoal were the main fuels in the Roman world, but non-wood fuels including agricultural waste (especially olive pressings), were also consumed. This paper reviews the types of fuel used in the preparation of food, both commercially and domestically, with reference to examples from the Greco-Roman world, especially Pompeii. The relative heat values of different fuels are discussed, together with an overview of the supply constraints and probable volumes required.