Drosophila melanogaster (Greek for dark-bellied dew lover : δρόσος = dew, φίλος = lover, μέλας = dark-coloured, γαστήρ = belly) is a species of Diptera, or the order of flies, in the family Drosophilidae. The species is known generally as the common fruit fly or vinegar fly. Starting from Charles W. Woodworth, this species is a model organism that is widely used for biological research in studies of genetics, physiology, microbial pathogenesis and life history evolution. It is typically used because it is an animal species that is easy to care for, breeds quickly, and lays many eggs.

Flies belonging to the family Tephritidae are also called fruit flies, which can lead to confusion, especially in Australia and South Africa, where the term fruit fly refers to members of the Tephritidae that are economic pests in fruit production, such as Ceratitis capitata, the Mediterranean fruit fly or "Medfly".

Wildtype fruit flies have brick red eyes, are yellow-brown in color, and have transverse black rings across their abdomen. They exhibit sexual dimorphism: females are about 2.5 millimeters (0.098 in) long; males are slightly smaller and the back of their bodies is darker. Males are easily distinguished from females based on color differences, with a distinct black patch at the abdomen, less noticeable in recently emerged flies (see fig), and the sexcombs (a row of dark bristles on the tarsus of the first leg). Furthermore, males have a cluster of spiky hairs (claspers) surrounding the reproducing parts used to attach to the female during mating. There are extensive images at FlyBase.

Fruit fly may refer to several organisms:

Fruit fly may also refer to: