The common pheasant (Phasianus colchicus), ring-necked pheasant, or blue-headed pheasant, is a bird in the pheasant family (Phasianidae). The genus name comes from Latin phasianus 'pheasant'. The species name colchicus is Latin for 'of Colchis' (modern day Georgia), a country on the Black Sea where pheasants became known to Europeans. Although Phasianus was previously thought to be closely related to the genus Gallus, the genus of junglefowl and domesticated chickens, recent studies show that they are in different subfamilies, having diverged over 20 million years ago.
It is native to Asia, where it is widespread, and also the extreme southeast of Europe in the northern foothills of the Caucasus Mountains. It has been widely introduced elsewhere as a game bird. In parts of its range, mainly in places where none of its relatives occur such as in Europe, where it is naturalised, it is simply known as the "pheasant". Ring-necked pheasant is both the collective name for a number of subspecies and their intergrades that have white neck rings, and the name used for the species as a whole in North America.