The common chaffinch or simply the chaffinch (Fringilla coelebs) is a common and widespread small passerine bird in the finch family. The male is brightly coloured with a blue-grey cap and rust-red underparts. The female is more subdued in colouring, but both sexes have two contrasting white wing bars and white sides to the tail. The male bird has a strong voice and sings from exposed perches to attract a mate.

The chaffinch breeds in much of Europe, across the Palearctic to Siberia and in northwestern Africa. The female builds a nest with a deep cup in the fork of a tree. The clutch is typically four or five eggs, which hatch in about 13 days. The chicks fledge in around 14 days, but are fed by both adults for several weeks after leaving the nest. Outside the breeding season, chaffinches form flocks in open countryside and forage for seeds on the ground. During the breeding season, they forage on trees for invertebrates, especially caterpillars, and feed these to their young. They are partial migrants; birds breeding in warmer regions are sedentary, while those breeding in the colder northern areas of their range winter further south.

The eggs and nestlings of the chaffinch are taken by a variety of mammalian and avian predators. Its large numbers and huge range mean that chaffinches are classed as of least concern by the International Union for Conservation of Nature.