Tomsk is a city and the administrative center of Tomsk Oblast in Russia, located on the Tom River. Population: 556,478 ; 524,669 ; 487,838 ; …Tomsk is a city and the administrative center of Tomsk Oblast in Russia, located on the Tom River. Population: 556,478 ; 524,669 ; 487,838 ; 501,963. Founded in 1604, Tomsk is one of the oldest cities in Siberia. The city is a notable educational and scientific center with six state universities consisting of over 100,000 students, including Tomsk State University, the oldest university in Siberia.