Tomsk Oblast (region) is a federal subject of Russia (an oblast). It lies in the southeastern West Siberian Plain, in the southwest of the Siberian Federal District.

The development of the territory which now belongs to the oblast began in the early 17th century. Tomsk itself was founded in 1604. Most of the oblast's territory is inaccessible because it is covered with taiga woods and swamps. The oblast shares borders with Krasnoyarsk Krai, Tyumen, Omsk, Novosibirsk, and Kemerovo Oblasts.

Tomsk Oblast is rich in natural resources, particularly oil, natural gas, ferrous and non-ferrous metals, peat, and underground waters. Forests are also among the most significant assets of the oblast: about 20% of the West Siberian forest resources are located in Tomsk Oblast.