The common 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", 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.

Pheasants are birds of several genera within the family Phasianidae in the order Galliformes. Although they can be found all over the world in introduced populations, the pheasant genera native range is restricted to Eurasia. The classification "pheasant" is paraphyletic, as birds referred to as pheasants are included within both the subfamilies Phasianinae and Pavoninae, and in many cases are more closely related to smaller phasianids, grouse, and turkey than to other pheasants.