Udomlya is a town located in the Tver Oblast of Russia. It serves as the administrative center of the Udomelsky District and is situated on the shores of Lake Pesvo along the Rybinsk–Bologoye railway. The town is positioned approximately 225 kilometers (140 mi) north of Tver, which is the administrative center of the oblast.
According to census data, the population of Udomlya has remained relatively stable over recent decades. The 2010 census recorded a population of 31,061, following a figure of 31,961 in 2002 and 30,751 during the 1989 Soviet census.