Tver Oblast (Russian: Тверска́я о́бласть, Tverskaya oblast) is a federal subject of Russia (an oblast). Its administrative center is the city of Tver. From 1935 to 1990, it was named Kalinin Oblast (Кали́нинская о́бласть) after Mikhail Kalinin. Population: 1,353,392 (2010 Census).