Smolensk Oblast (Russian: Смоле́нская о́бласть, Smolenskaya oblast) is a federal subject of Russia (an oblast). Its administrative center is the city of Smolensk. As of the 2010 Census, its population was 985,537.

The oblast was founded on September 27, 1937. It borders Pskov Oblast in the north, Tver Oblast in the northeast, Moscow Oblast in the east, Kaluga Oblast in southwest, Bryansk Oblast in the south, and Mogilev and Vitebsk Oblasts of Belarus, in the west and northwest, as part of the Belarus–Russia border.

The main river of the region is the Dnieper River and its tributaries, Desna, Vop, Vyazma. By the rivers of the Volga basin and its tributary Vazuza Gzhat and tributary of the Oka river, Ugra. To the north-west flows a short section of the Western Dvina River and its tributary river Kasplya .

Among the major reservoirs supplying water are Moscow Vazuzssky Yauza and reservoirs in the north-east, as well as cooling power plants - Smolensk reservoir in the north near the village of Lake and Desnogorsk Reservoir in the south area of the city near the Desnogorsk .

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