An anchovy is a small, common salt-water forage fish of the family Engraulidae.

The 144 species are placed in 17 genera; they are found in the Atlantic, Indian, and Pacific Oceans, and in the Black Sea and the Mediterranean Sea. Anchovies are usually classified as oily fish.

Anchovies are small, green fish with blue reflections due to a silver-colored longitudinal stripe that runs from the base of the caudal fin. They range from 2 to 40 cm (0.79 to 15.75 in) in adult length, and their body shapes are variable with more slender fish in northern populations.

The snout is blunt with tiny, sharp teeth in both jaws. The snout contains a unique rostral organ, believed to be sensory in nature, although its exact function is unknown. The mouth is larger than that of herrings and silversides, two fish which anchovies closely resemble in other respects. The anchovy eats plankton and recently hatched fish.

Anchovies are found in scattered areas throughout the world's oceans, but are concentrated in temperate waters, and are rare or absent in very cold or very warm seas. They are generally very accepting of a wide range of temperatures and salinity. Large schools can be found in shallow, brackish areas with muddy bottoms, as in estuaries and bays. They are abundant in the Mediterranean, particularly in the Alboran Sea, Aegean Sea and the Black Sea. The species is regularly caught along the coasts of Crete, Greece, Sicily, Italy, France, Turkey, and Spain. They are also found on the coast of northern Africa. The range of the species also extends along the Atlantic coast of Europe to the south of Norway. Spawning occurs between October and March, but not in water colder than 12 ºC (54 ºF). The anchovy appears to spawn at least 100 km (62 mi) from the shore, near the surface of the water.

The anchovy is a significant food source for almost every predatory fish in its environment, including the California halibut, rock fish, yellowtail, shark, chinook, and coho salmon. It is also extremely important to marine mammals and birds; for example, breeding success of California brown pelicans and elegant terns is strongly connected to anchovy abundance.

A traditional method of processing and preserving anchovies is to gut and salt them in brine, allow them to mature, and then pack them in oil or salt. This results in a characteristic strong flavor and the flesh turns deep grey. Pickled in vinegar, as with Spanish boquerones, anchovies are milder and the flesh retains a white color. In Roman times, anchovies were the base for the fermented fish sauce garum. Garum had a sufficiently long shelf life for long-distance commerce, and was produced in industrial quantities. Anchovies were also eaten raw as an aphrodisiac. Today, they are used in small quantities to flavor many dishes. Because of the strong flavor, they are also an ingredient in several sauces and condiments, including Worcestershire sauce, Caesar salad dressing, remoulade, Gentleman's Relish, many fish sauces, and in some versions of Café de Paris butter. For domestic use, anchovy fillets are packed in oil or salt in small tins or jars, sometimes rolled around capers. Anchovy paste is also available. Fishermen also use anchovies as bait for larger fish, such as tuna and sea bass.

The strong taste people associate with anchovies is due to the curing process. Fresh anchovies, known in Italy as alici, have a much milder flavor. In Sweden and Finland, the name anchovies is related strongly to a traditional seasoning, hence the product "anchovies" is normally made of sprats and herring can be sold as "anchovy-spiced". Fish from the Engraulidae family are instead known as sardell in Sweden and sardelli in Finland, leading to confusion when translating recipes.