The genetic diversity of present-day brown bears (Ursus arctos) has been extensively studied over the years and appears to be geographically structured into five main clades based upon analysis of the mtDNA.

[11] It is known from mtDNA studies that during the Pleistocene ice age it was too cold for the brown bear to survive in Europe except in three places: Russia, Spain, and the Balkans.

[12] However, a newer study found that brown bears were present in France and Belgium during the Last Glacial Maximum as well, indicating they were not as restricted to southern refugia as previously thought.

Probably their ancestors survived the ice age in the ice-free areas west of the Ural Mountains, and thereafter spread to Northern Europe.

[25] Globally, the largest population is found east of the Ural mountain range, in the large Siberian forests; brown bears are also present in smaller numbers in parts of central Asia.

The largest brown bear population in Europe is in Russia, where it has now recovered from an all-time low caused by intensive hunting.

Large populations can also be found in Romania (around 6,000), Slovakia (around 1,200), Bosnia and Herzegovina, Croatia (1,200), Slovenia (1,100),[27] North Macedonia, Bulgaria, Poland, Turkey, and Georgia.

[39][40] The historic distribution of bears and the impression the Eurasian brown bear has made on people are reflected in the names of several localities (some notable examples include Bern, Medvednica, Otepää and Ayu-Dag), as well as personal names—for example, Xiong, Bernard, Arthur, Ursula, Urs, Ursicinus, Orsolya, Björn, Nedved, Medvedev, and Otso.

The European brown bear was once common in Germany and alpine lands like Northern Italy, Eastern France, and most of Switzerland, and thus appears in tales of various dialects of German.

It is also Finland's national animal;[41] and in Croatia, a brown bear is depicted on the reverse of the Croatian 5 kuna coin, minted from 1993 to 2023.