Bison occidentalis is an extinct species of bison that lived in North America, from about 11,700 to 5,000 years ago, spanning the end of the Pleistocene to the mid-Holocene.

[3] However, as the type specimen of B. occidentalis is from Alaska, other authors have argued that the species should be restricted to remains that region, with suggestions that true B. occidentalis evolved locally in the region from steppe bison (Bison priscus) around 13,000 years ago.

[4] Due to this uncertainty, specimens that likely represent intermediates between B. antiquus and B. bison in central North America have been referred to as B.

[3] Some authors have suggested that B. bison descends from hybridization between true B. occidentalis migrating into central North America from Alaska and central North American B. antiquus, though this suggestion has been rejected by other authors who suggest that B. bison evolved from B. antiquus alone.

[4] Some authors include remains found in continental Eurasia[5][6][7] and the Japanese archipelago.