Estonia ( Estonian : Eesti ), officially the Republic of Estonia ( Estonian : Eesti Vabariik ); is a country located in the Baltic region in northern Europe . It is bordered on the north by the Gulf of Finland , on the west by the Baltic Sea , on the south by Latvia (343 km), to the east by Lake Pepos and the Russian Federation (338.6 km).  . Estonia covers 45,227 square kilometers (17,462) square miles, and its seasonal climate is mild. Estonian is the only official language in the country. Estonia is a parliamentary democratic republic , divided into 15 provinces. The capital and its largest city, the capital, Tallinn . It has a population of 1,319,133 million people . It is also one of the least-developed members of the population in the European Union , the euro area , and the North Atlantic Treaty Organization . It has the highest GDP per capita among the former Soviet republics.  The Republic of Estonia has been described as a "high-income economy" by the World Bank and a "developed economy" by the International Monetary Fund , and later became a member of the Organization for Economic Cooperation and Development . The United Nations ranks Estonia as a developed country, and the Human Development Index is very high.It also has a high level of freedom of the press, economic freedom, political freedom, and education.