The Biya River (Russian: Бия) is a river in the Altai Republic and Altai Krai in Russia. It forms the Ob River as it joins the Katun River. The Biya River is 301 km long; the area of its drainage basin is 37,000 km². It flows out of the Teletskoye Lake. The river freezes up during the mid-November to early December (some parts of the river freeze over on a year-to-year basis). It breaks up in the early or mid-April.