Social Democratic Party of Lithuania

Social Democratic Party of Lithuania
Lietuvos socialdemokratų partija
AbbreviationLSDP
ChairpersonMindaugas Sinkevičius (acting)
First Deputy ChairVacant
Deputy Chairs
Executive SecretaryJustas Pankauskas
Founded1 May 1896 (1896-05-01)
HeadquartersB. Radvilaitės g. 1, Vilnius
Youth wingLietuvos socialdemokratinio jaunimo sąjunga (LSDJS)
Membership (2022) 15,205
IdeologySocial democracy
Political positionCentre-left
European affiliationParty of European Socialists
European Parliament groupProgressive Alliance of Socialists and Democrats
International affiliationProgressive Alliance
Socialist International
Colours  Red
Seimas
52 / 141
European Parliament
2 / 11
Municipal councils
358 / 1,498
Mayors
17 / 60
Website
lsdp.lt

The Social Democratic Party of Lithuania (Lithuanian: Lietuvos socialdemokratų partija, LSDP) is a centre-left and social democratic political party in Lithuania. Founded as an underground Marxist organisation in 1896, it is the oldest extant party in Lithuania. During the Soviet occupation, the party ceased to exist. The party reemerged after the fall of the Soviet Union and the end of communist rule in 1989.

The party led a government in the unicameral Seimas, Lithuania's parliament from 2001 to 2008 and from 2012 to 2016. It has been the ruling party of Lithuania since 2024. The party is a member of the Party of European Socialists (PES), Progressive Alliance, and Socialist International.