A staple food is one that is eaten regularly and in such quantities that it constitutes a dominant portion of a diet, and that supplies a high proportion of energy and nutrient needs. Most people live on a diet based on at most a small number of staples.

Staple foods vary from place to place, but are typically inexpensive or readily available foods that supply one or more of the three macronutrients needed for survival and health: carbohydrate, protein, and fat. Typical examples include grains, tubers, legumes, or seeds. The staple food of a specific society may be eaten as often as every day, or every meal. Early civilizations valued staple foods because, in addition to providing necessary nutrition, they can usually be stored for a long period of time without decay. Some foods are only staples during seasons of shortage, such as dry seasons or cold-temperate winters, against which times harvests have been stored; during seasons of plenty wider choices of foods may be available.

Most staple foods derive either from cereals such as wheat, barley, rye, maize, or rice, or starchy tubers or root vegetables such as potatoes, yams, taro, and cassava. Other staple foods include pulses (dried legumes), sago (derived from the pith of the sago palm tree), and fruits such as breadfruit and plantains. Staple foods may also contain, depending on the region, sorghum, olive oil, coconut oil and sugar.