To assess the origins of the modern Western Siberian populations, measurements of 30 recent male cranial samples from that territory and 56 medieval ones from Siberia, Southwestern Central Asia, Kazakhstan, and the Volga–Ural area were processed using canonical variate analysis, and Mahalanobis distances corrected for sample size were calculated. The distance matrix was subjected to nonmetric multidimensional scaling and cluster analysis. Ties with modern groups are the most evident in people associated with the Srostki culture of northwestern Altai, Ryolka and Ust-Ishim cultures, Mongolian Age dwellers of Baraba, Gorny Altai, and the lower Tom, and the Yenisei Kyrgyz. Biological differentiation in Southern and Western Siberia is related to language—Ugric, Samoyedic, and Turkic speaking groups show signifi cant differences with regard to their cranial characteristics. Ugric samples differ much sharper than do Samoyedic or Turkic ones. Comparison with medieval samples provides no clues as to the origin of Ugrians. The southern Khanty attribution of Ryolka culture is not supported. Various groups of Selkups may have originated from Mongolic Age people of Baraba or from those of Ryolka and Ust-Ishim cultures. The cranial characteristics of Nenets are typologically Southern Siberian rather than Uralic, and they resemble Turks. The difference between northern Samoyeds and Selkups is likely due to a complex composition and wide geographic distribution of the proto-Samoyedic community. Selkup roots of the Tom Tatars and the Eastern Central Asiatic tendency of Beltyr Khakas are revealed, and the Yenisei Kyrgyz roots of Kachi Khakas are demonstrated. In contrast to their linguistic isolation, Kets display no cranial specifi city.