Poland (Polish: Polska), officially the Republic of Poland (Polish: Rzeczpospolita Polska (help·info)), is a country located in Central Europe. It is bordered by Germany to the west, the Czech Republic and Slovakia to the south, Ukraine and Belarus to the east, and the Baltic Sea, Lithuania, and Russia (in the form of the Kaliningrad Oblast exclave) to the north. Poland shares a maritime border with Denmark in the Baltic Sea. The country has been a member state of the European Union since May 1, 2004.

The Polish state was formed more than 1,000 years ago under the Piast dynasty, and reached its golden age near the end of the 16th century under the Jagiellonian dynasty, when Poland was one of the largest, wealthiest, and most powerful countries in Europe. In 1791 the Sejm of the Polish-Lithuanian Commonwealth adopted the Constitution of May 3, Europe's first modern codified constitution, and the second in the world after the Constitution of the United States. Soon afterwards, the country ceased to exist after being partitioned by its neighbours Russia, Austria, and Prussia. It regained independence in 1918 in the aftermath of the First World War as the Second Polish Republic. Following the Second World War it became a communist satellite state of the Soviet Union known as the People's Republic of Poland. In 1989 the first partially-free elections in Poland's post-World War II history concluded the Solidarity (Solidarność) movement's struggle for freedom and resulted in the defeat of Poland's communist rulers. The current Third Polish Republic was established, followed a few years later by the drafting of a new constitution in 1997. In 1999 Poland acceded to NATO, and in 2004 it joined the European Union.

Officially the country is known as Republic of Poland, in Polish Rzeczpospolita Polska. The word Rzeczpospolita is the historic name that has been used continuously since the 16th century during the Polish-Lithuanian Commonwealth, which was an elective monarchy. The term Rzeczpospolita can mean "commonwealth" or also "republic", whereas the Polish translation for the English term "republic" is republika. During communist rule from 1952 to 1989 the country's official name was the People's Republic of Poland (Polska Rzeczpospolita Ludowa), which was the only break in the historical official designation.