- Eastern Europe is a subregion of the European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural, and socio-economic connotations. Its eastern boundary is marked by the Ural Mountains, whilst its western boundary is defined in various ways. Most definitions include the countries of Belarus, Russia, Ukraine, Moldova and Romania while less restrictive definitions may also include some or all of the Balkans, the Baltic states, the Caucasus and the VisegrĂĄd group.