The Mologa is a river in Maksatikhinsky, Bezhetsky, Lesnoy, and Sandovsky Districts of Tver Oblast, Pestovsky District in Novgorod Oblast, and Ustyuzhensky and Cherepovetsky Districts in Vologda Oblast Russia. It is a left tributary of the Volga. The lower course of the Mologa has been turned into the Rybinsk Reservoir. It is 456 kilometres (283 mi) long, and the area of its basin 29,700 square kilometres (11,500 sq mi). The principal tributaries of the Mologa are the Osen (right), the Volchina (left), the Kobozha (left), the Chagodoshcha (left) and the Sit.

Pestovo is a town and the administrative center of Pestovsky District in Novgorod Oblast, Russia, located in the Valdai Hills on the Mologa River. Population: 15,903 (2010 Russian census); 15,990 (2002 Census); 15,941 (1989 Soviet census).