Politics of Lithuania takes place in a framework of a unitary semi-presidential representative democratic republic,^[1][2][3][4] whereby the president of Lithuania is the head of state and the prime minister of Lithuania is the head of government, and of a multi-party system.

Executive power is exercised by the president and the Government, which is headed by the prime minister. Legislative power is vested in both the Government and the unicameral Seimas (Lithuanian Parliament). Judicial power is vested in judges appointed by the president of Lithuania and is independent of executive and legislature power. The judiciary consists of the Constitutional Court, the Supreme Court, and the Court of Appeal as well as the separate administrative courts. The Constitution of the Republic of Lithuania established these powers upon its approval on 25 October 1992. Being a multi-party system, the government of Lithuania is not dominated by any single political party, rather it consists of numerous parties that must work with each other to form coalition governments. The Economist Intelligence Unit rated Lithuania a "flawed democracy" in 2022.^[5]

Since Lithuania restored independence on 11 March 1990, it has kept democratic traditions. Drawing from the interwar experiences, politicians made many different proposals that ranged from strong parliamentarism to a presidential republic with checks and balances similar to the United States. Through compromise, a semi-presidential system was settled.^[1] In a referendum on 25 October 1992, the first general vote of the people since their declared independence, 56.75% of the total number of voters supported the new constitution.^[6]

All major political parties declared their support for Lithuania's membership in NATO and the European Union (EU). Lithuania joined NATO on 29 March 2004.^[7] Lithuania joined the EU on 1 May 2004 and Schengen Area on 21 December 2007 and Eurozone on 1 January 2015.^[8]

Since 1991, Lithuanian voters have shifted from right to left and back again, swinging between the Conservatives, led by Vytautas Landsbergis, and the (formerly Communist) Democratic Labour Party of Lithuania, led by president Algirdas Brazauskas. During this period, the prime minister was Gediminas Vagnorius.

Valdas Adamkus was the president since 1998. His proposed prime minister was Rolandas Paksas, whose government got off to a rocky start and collapsed within seven months. The alternation between left and right was broken in the October 2000 elections when the Liberal Union and New Union parties won the most votes and were able to form a centrist ruling coalition with minor partners. President Adamkus played a key role in bringing the new centrist parties together. Artūras Paulauskas, the leader of the centre-left New Union (also known as the social-liberal party), became the Chairman of the Seimas. In July 2001, the centre-left New Union party forged an alliance with the Social Democratic Party of Lithuania and formed a new cabinet under former president Algirdas Brazauskas. On 11 April 2006, Artūras Paulauskas was removed from his position and Viktoras Muntianas was elected Chairman of the Seimas.^[9]

The cabinet of Algirdas Brazauskas resigned on 31 May 2006, as President Valdas Adamkus expressed no confidence in two of the Ministers, formerly party colleagues of Brazauskas, over ethical principles. Brazauskas decided not to remain in office as acting prime minister, and announced that he was finally retiring from politics.^[10] Even so, he led the ruling Social Democratic Party of Lithuania for one more year, until 19 May 2007, when he passed the reins to Gediminas Kirkilas. On 27 November 2008, Andrius Kubilius of conservative Homeland Union was appointed as a prime minister.^[11] In December 2012 Andrius Kubilius was succeeded by Algirdas Butkevičius after his Social Democratic Party became the biggest party in parliamentary elections.^[12]

In 2016, The Peasant and Green's Union (LGPU) won parliamentary elections. It secured 54 seats in the 141-member parliament (Seimas), making a previously small centrist agrarian party the biggest in parliament. The conservative Homeland Union won 30 seats. The ruling Social Democrats, led by Lithuania's Prime Minister Algirdas Butkevciu, lost heavily and secured just 17 seats.^[13] On 22 November 2016, Saulius Skvernelis of the Lithuanian Peasants and Greens Union, became new prime minister.^[14]

In October 2020, conservative opposition Homeland Union-Lithuanian Christian Democrats (TS-LKD) won parliamentary elections with 50 seats. Prime Minister Saulius Skvernelis' Union of Farmers and Greens came a distant second with just 32 seats.^[15] In November 2020, Ingrida Šimonytė became new prime minister, after forming a centre-right coalition government of her TS-LKD and two liberal parties.^[16]

Government in Lithuania is made up of three branches originally envisioned by enlightenment philosopher Baron de Montesquieu: executive, legislative, and judicial. Each branch is separate and is set up to do checks and balances on each other branch.

Lithuania has a three-tier administrative division: the country is divided into 10 counties (Lithuanian: singular – apskritis, plural – apskritys) that are further subdivided into 60 municipalities (Lithuanian: singular – savivaldybė, plural – savivaldybės) which consist of over 500 elderships (Lithuanian: singular – seniūnija, plural – seniūnijos).

The county governors (Lithuanian: apskrities viršininkas) institution and county administrations have been dissolved in 2010.^[23]

Municipalities are the most important administrative unit. Some municipalities are historically called "district municipalities", and thus are often shortened to "district"; others are called "city municipalities", sometimes shortened to "city". Each municipality has its own elected government. In the past, the election of municipality councils occurred once every three years, but it now takes place every four years. The council appoints elders to govern the elderships. Mayors are elected directly since 2015, being appointed by the council before that.^[24]