Udomelsky District is an administrative and municipal district (raion), one of the thirty-six in Tver Oblast, Russia. It is located in the north of the oblast and borders with Moshenskoy District of Novgorod Oblast in the north, Lesnoy District in the northeast, Maksatikhinsky District in the east, Vyshnevolotsky District in the south, Bologovsky District in the west, and with Borovichsky District of Novgorod Oblast in the west. The area of the district is 2,476.2 square kilometers (956.1 sq mi). Its administrative center is the town of Udomlya. Population: 40,292 ; 10,401 (2002 Census); 12,426 (1989 Soviet census). The population of Udomlya accounts for 77.1% of the district's total population.