The Kuloy is a river in Pinezhsky and Mezensky Districts of Arkhangelsk Oblast in Russia. Its mouth is located in the Mezen Bay of the White Sea. It is long, and the area of its basin . The principal tributaries of the Kuloy are the Kyolda (left), the Nemnyuga (right), and the Soyana (left). In the upper course, the Kuloy is known as the Sotka River; the total length of the Sotka and the Kuloy is .