Lithuania, officially the Republic of Lithuania, is a country in northern Europe. Situated along the south-eastern shore of the Baltic Sea, it shares borders with Latvia to the north, Belarus to the southeast, Poland, and the Russian exclave of the Kaliningrad Oblast to the southwest. Lithuania has been a member state of the European Union since 1 May 2004.

Since Lithuania declared independence on March 11, 1990, it has kept strong democratic traditions. In the first general elections after the independence on October 25, 1992, 56.75% of the total number of voters supported the new constitution. Drafting the constitution was a long and complicated process. The role of the President fuelled the most heated debates. Drawing from the interwar experiences, politicians made many different proposals ranging from strong parliamentarism to the United States' model. Eventually a compromise semi-presidential system was agreed upon.

The Lithuanian head of state is the President, elected directly for a five-year term; he or she may serve a maximum of two consecutive terms. The post of President is largely ceremonial with functions of overseeing foreign affairs and national security policy. The President is also the commander-in-chief. The President, with the approval of the parliamentary body, the Seimas, also appoints the prime minister and on the latter's nomination, appoints the rest of the cabinet, as well as a number of other top civil servants and the judges for all courts. The judges of the Constitutional Court (Konstitucinis Teismas), who serve for nine year terms, are appointed by the President (three judges), the Chairman of the Seimas (three judges) and the chairman of the Supreme Court (three judges). The unicameral Lithuanian parliament, the Seimas, has 141 members who are elected to four-year terms. 71 of the members of this legislative body are elected in single constituencies, and the other 70 are elected in a nationwide vote by proportional representation. A party must receive at least 5% of the national vote to be represented in the Seimas

Lithuania is situated in northern Europe. It has around 99 kilometres (61.5 mi) of sandy coastline, of which only about 38 kilometres (24 mi) face the open Baltic Sea; the rest of the coast is sheltered by the Curonian sand peninsula. Lithuania's major warm-water port, Klaipeda, lies at the narrow mouth of the Curonian Lagoon (Lithuanian: Kuršiu marios), a shallow lagoon extending south to Kaliningrad. The main river, the Neman River, and some of its tributaries carry international shipping vessels.

The Lithuanian landscape has been smoothed by glaciers. The highest areas are the moraines in the western uplands and eastern highlands, none of which are taller than 300 metres (1,000 ft) above sea level, with the maximum elevation being Aukštojas Hill at 294 metres (964 feet). The terrain features numerous lakes, Lake Vištytis for example, and wetlands; a mixed forest zone covers 30% of the country. The climate lies between maritime and continental, with wet, moderate winters and summers. According to one geographical computation method, Lithuania's capital, Vilnius, lies only a few kilometres south of the geographical centre of Europe.