Tomsk is a city and the administrative center of Tomsk Oblast in Russia, on the Tom River. Population: 556,478 ; 524,669 ; 487,838 ; 501,963…Tomsk is a city and the administrative center of Tomsk Oblast in Russia, 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. It has six universities, with over 100,000 students, including Tomsk State University, the oldest university in Siberia.