Whitebait is a collective term for the immature fry of fish, typically between 25 and 50 millimetres (1 and 2 in) long. Such young fish often travel together in schools along coasts, and move into estuaries and sometimes up rivers where they can be easily caught using fine-meshed fishing nets. Whitebaiting is the activity of catching whitebait.

Individual whitebait are tender and edible. The entire fish is eaten — including head, fins, bones, and bowels. Some species make better eating than others, and the particular species that are marketed as "whitebait" vary in different parts of the world.

As whitebait consists of immature fry of many important food species (such as herring, sprat, sardines, mackerel, bass and many others) it is not an ecologically viable foodstuff and several countries impose strict controls on harvesting.

The Alboran Sea is the westernmost element of the Mediterranean Sea. Whitebait have been consumed as a favoured element of the diet of peoples living along the northern coasts of the Alboran Sea in Spain, even though sale of these products has been banned.

In Australia whitebait refers to the juvenile stage of several predominantly galaxias species during their return to freshwater from the marine phase of their lifecycle.

Species referred to as whitebait in Australia include common galaxias G. maculatus, climbing galaxias G. brevipinnis, spotted galaxias G. truttaceus, Tasmanian whitebait Lovettia sealii, Tasmanian mudfish Neochanna cleaveri, and Tasmanian smelt Retropinna tasmanica.

Whitebait were once subject to a substantial commercial fishery but today only recreational fishers are permitted to gather them, under strict conditions and for a limited season.

Chinese whitebait is raised in fish farms and plentiful quantities are produced for export. The frozen product is commonly available in food stores and supermarkets at reasonable prices. The Chinese name for these is often translated as "silver fish" in English.