Eastern Europe is the eastern part of the European continent. There is no consensus as to the precise area it refers to, partly because the term has a wide range of geopolitical, geographical, cultural, and socioeconomic connotations.

The Eastern Europe sub-region includes Russia, Ukraine, Belarus, Romania and Moldova. Russia is the largest of all of the Eastern European countries, while Moldova is one of the smallest. It is so small that it is often thought to be part of Romania.

The East Central Europe sub-region consists of the Czech Republic, Hungary, Poland, Croatia, Slovenia and Slovakia. The Czech Republic and Slovakia, now two separate independent countries, were both part of Czechoslovakia from just after World War II until 1993. Both Slovenia and Croatia gained independence from the former Yugoslavia in 1991.

The Baltics sub-region comprises Lithuania, Latvia and Estonia, three north-eastern European countries situated along the coast of the Baltic Sea. All three were part of the Soviet Union until Lithuania declared its formal independence in 1990, and Latvia and Estonia followed in 1991.

The Balkans sub-region includes the countries of Bulgaria, Serbia, Montenegro, Bosnia and Herzegovina, Albania, Kosovo and Macedonia. Serbia, Montenegro, Bosnia and Herzegovina, Kosovo and Macedonia were also part of the former Yugoslavia.