Flavor (AmE) or flavour (CwE) is the sensory impression of a food or other substance. It is determined by the three chemical senses of taste, olfaction (smell), and the so-called trigeminal senses, which detect chemical irritants in the mouth and throat. The taste of many foods is often altered with flavorings.

Flavorings can be either natural or artificial, and they are added to many foods made in a factory. There are also so-called nature-identical flavorings, which are the chemical equivalent of natural flavors, only chemically synthesised rather than being extracted from the original source.

To begin producing artificial flavors, manufacturers must first find out the molecular structure of the compound that produces the desired flavor. To do this, the volatile substance that produces the natural flavor must first be extracted from the source substance. The methods of extraction can involve boiling, leeching, or using force to squeeze it out. This concentrated extract is then passed through a chromatograph, either in liquid or gaseous form. This will provide the requisite information about how the molecules are structured that are needed to produce the taste. The compound can then be artificially mass-produced for the market, although it is often difficult to produce an exact match to the original flavor.

Many of the compounds used to produce artificial flavor belong to a chemical category of esters. The list of known flavoring agents includes hundreds of molecular compounds, and the flavor chemist (flavorist) can often mix these together to produce many of the common flavors. Food manufacturers are often reluctant informing consumers about the source from where the flavor is obtained and whether it has been produced with the incorporation of substances such as animal by-products glycerin, gelatin the like and the use of alcohol in the flavors. Muslims, Orthodox Jews and Hindus adhere to religious laws, and vegans to personal morals, that restrict the use of animal by-products and alcohol in foods unless subject to overseeing and inspection by their respective religious authority or less-strict or circumstantial moral belief.

Flavor enhancers are also used to augment the taste of foods.

The compounds used to produce artificial flavors are almost identical to those that occur naturally, and a natural origin for a substance does not necessarily imply that it is safe to consume. In fact, artificial flavors are considered somewhat safer to consume than natural flavors. Natural flavors may contain toxins from their sources while artificial flavors are typically more pure and are required to undergo more testing before being sold for consumption.

Legal definition (U.S.)

According to the U.S. Code of Federal Regulations, a natural flavor is "the essential oil, oleoresin, essence or extractive, protein hydrolysate, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or any other edible portions of a plant, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose primary function in food is flavoring rather than nutritional." An artificial flavor is one that does not meet the specifications listed above.