Western Siberia or West Siberia (Russian: Западная Сибирь) is a part of Siberia. The area of the region is 2.5 million square kilometres. Nearly 80% of the Western Siberia's area is located within the West Siberian Plain. The largest rivers of the region is the Irtysh and the Obi.
The most populous city of Western Siberia is the city of Novosibirsk. Other major cities include: