Food in ancient Rome reflects both the variety of food-stuffs available through the expanded trade networks of the Roman Empire and the traditions of conviviality from ancient Rome's earliest times, inherited in part from the Greeks and Etruscans. In contrast to the Greek symposium, which was primarily a drinking party, the equivalent social institution of the Roman convivium (dinner party) was focused on food. Banqueting played a major role in Rome's communal religion. Maintaining the food supply to the city of Rome had become a major political issue in the late Republic, and continued to be one of the main ways the emperor expressed his relationship to the Roman people and established his role as a benefactor. Roman food vendors and farmers' markets sold meats, fish, cheeses, produce, olive oil and spices; and pubs, bars, inns and food stalls sold prepared food.

Bread was an important part of the Roman diet, with more well-to-do people eating wheat bread and poorer people eating that made from barley. Fresh produce such as vegetables and legumes were important to Romans, as farming was a valued activity. A variety of olives and nuts were eaten. While there were prominent Romans who discouraged meat eating, a variety of meat products were prepared, including blood puddings, sausages, cured ham and bacon. The milk of goats or sheep was thought superior to that of cows; milk was used to make many types of cheese, as this was a way of storing and trading milk products. While olive oil was fundamental to Roman cooking, butter was viewed as an undesirable Gallic foodstuff. Sweet foods such as pastries typically used honey and wine-must syrup as a sweetener. A variety of dried fruits (figs, dates and plums) and fresh berries were also eaten.

Salt, which in its pure form was an relatively expensive commodity in Rome, was the fundamental seasoning. The most common salty condiment was a fermented fish sauce known as garum. Locally available seasonings included garden herbs, cumin, coriander, and juniper berries. Imported spices included pepper, saffron, cinnamon, and fennel. While wine was an important beverage, Romans looked down on drinking to excess and drank their wine mixed with water; drinking wine "straight" was viewed as a barbarian custom.

The main Roman ingredients in dishes were wheat, wine, meat and fish, bread, and sauces and spices. The richer Romans had luxurious lives, and sometimes hosted banquets or feasts.

Most people would have consumed at least 70 percent of their daily calories in the form of cereals and legumes. Grains included several varieties of wheat—emmer, rivet wheat, einkorn, and spelt—as well as the less desirable barley, millet, and oats.

Legumes included the lentil, chickpea, bitter vetch, broad bean, garden pea, and grass pea; Pliny names varieties such as the Venus pea, and poets praise Egyptian lentils imported from Pelusium. Legumes were planted in rotation with cereals to enrich the soil, and were stockpiled in case of famine. The agricultural writer Columella gives detailed instructions on curing lentils, and Pliny says they had health benefits. Although usually thought of as modest fare, legumes also appear among the dishes at banquets.

Puls (pottage) was considered the aboriginal food of the Romans, and played a role in some archaic religious rituals that continued to be observed during the Empire. The basic grain pottage could be elaborated with chopped vegetables, bits of meat, cheese, or herbs to produce dishes similar to polenta or risotto. "Julian stew" (Pultes Iulianae) was made from spelt to which was added two kinds of ground meat, pepper, lovage, fennel, hard bread, and a wine reduction; according to tradition, it was eaten by the soldiers of Julius Caesar and was a "quintessential Roman dish."

Urban populations and the military preferred to consume their grain in the form of bread. The lower classes ate coarse brown bread made from emmer or barley. Fine white loaves were leavened by wild yeasts and sourdough cultures. The beer-drinking Celts of Spain and Gaul were known for the quality of their breads risen with barm or brewers' yeast. The poem Moretum describes a flatbread prepared on a griddle and topped with cheese and a pesto-like preparation, somewhat similar to pizza or focaccia.