| Country | Name | Abbr | Notes |
|---|
Albania | Social Democratic Party of Albania[150] | PSD | Admitted as consultative member in 1992.[46] Promoted to full member in 1996.[47][150] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Algeria | National Liberation Front | FLN | Expelled following the2019 Algerian protests. |
Andorra | New Democracy | ND | Admitted as consultative member in 1999.[41] |
Antigua and Barbuda | Antigua and Barbuda Labour Party | ALP | Admitted as consultative member in 2008.[65] |
Argentina | Popular Socialist Party | PSP | Admitted as full member in 1992.[46] Merged with theDemocratic Socialist Party to form theSocialist Party. |
| Socialist Party[151][152] | PS | Full member since 1951.[152] |
Azerbaijan | Azerbaijani Social Democratic Party | ASDP | Admitted as observer member in 1996.[47] Promoted to consultative member in 2003.[42] Readmitted as consultative member in June/July 2014.[66] Admitted as full member in 2016.[62] Party dissolved in 2023.[153] |
Aruba | People's Electoral Movement[50] | MEP | Promoted to full member in 1992.[46] Full member since 1994.[50] Delisted in December 2014. |
Australia | Australian Labor Party[154] | ALP | Admitted as full member in 1966.[154] Delisted in December 2014. |
Austria | Social Democratic Party of Austria | SPÖ | Admitted as a full member in 1951.[155] Delisted in 2022. |
Barbados | Barbados Labour Party[156] | BLP | Admitted as full member in 1987.[156] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Belgium | Belgian Socialist Party | PSB/BSP | Founder member. Split in 1978. |
| Forward | | Delisted in 2017. |
Benin | Democratic Union of Progressive Forces | UDFP | Admitted as observer member in 1992.[46] |
| Social Democratic Party[157] | PSD | Admitted as consultative member in 1999.[41][157] Promoted to full member in 2003.[42][157] |
Bosnia and Herzegovina | Alliance of Independent Social Democrats | SNSD | Admitted as consultative member in 2003.[42] Promoted to full member in 2008[65] Expelled in August 2012.[92] |
Botswana | Botswana National Front | BNF | Admitted as observer member in 1996.[47] |
Bolivia | Revolutionary Left Movement[158] | MIR | Admitted as consultative member in 1986.[58] Consultative member in 1987.[158] Promoted to full member in 1992.[46][158] |
Bulgaria | Bulgarian Euro-Left | BEL[159] | Admitted as observer member in 1999.[41] |
Burkina Faso | Party for Democracy and Progress / Socialist Party[67] | PDP/PS | Admitted as full member circa 1995.[67] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Burundi | Front for Democracy in Burundi | FRODEBU | Admitted as consultative member in 2003.[42] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Canada | Co-operative Commonwealth Federation | CCF | Became theNew Democratic Party in 1961. |
Canada | New Democratic Party[160] | NDP/NPD | Delisted in 2018.[161][failed verification] |
Central African Republic | Movement for Democracy and Social Progress | MDPS | Admitted as observer member in 1992.[46] |
Iran | Kurdistan Democratic Party | KDP | Admitted as a full member in November 2015.[54] Party dissolved in 2022.[162] |
Kyrgyzstan | Social Democratic Party of Kyrgyzstan | SDPK | [163] |
Ivory Coast | Ivorian Popular Front[164] | FPI | Admitted as consultative member in 1992.[46] Promoted to full member in 1996.[47][164] Expelled in March 2011.[21] |
Colombia | Alternative Democratic Pole | PDA | Former observer member. Delisted in December 2014. |
| M-19 Democratic Alliance | AD/M-19 | Admitted as observer member in 1992.[46] |
Curaçao | Partido MAN | MAN | Promoted to full member in 1989.[59] Delisted in 2017. |
Denmark | Social Democrats | SD | Founding member. Withdrew in 2017. |
Dominica | Dominica Labour Party | DLP | Admitted as consultative member in 1996.[47] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Ecuador | Democratic Left[165] | PID | Member since 1987.[165] Delisted in 2017. |
Egypt | Egyptian Social Democratic Party | ESDP (or HMDI inArabic) | Admitted as consultative member in 2012.[92] Promoted to full member in November 2015.[54] Delisted in 2019 due to non-payment of membership fees. |
| National Democratic Party[71] | NDP | Admitted as full member in 1989.[59] Full member since 1992.[71] Expelled in January 2011.[166][167][168] |
El Salvador | Democratic Party | PD | Admitted as observer member in 1996.[47] |
Estonia | Social Democratic Party[169][170] | SDE | Member since 1990.[170] Withdrew in 2017. |
Fiji | Fiji Labour Party | FLP | Admitted as consultative member in 1992.[46] Expelled in 2008, due to the party's participation in a government issued from amilitary coup.[65] |
France | French Section of the Workers' International | SFIO | Founding member. Member in 1951–1969. |
Georgia | Union of Citizens of Georgia | CUG | Admitted as observer member in 1996.[47] Party disbanded in 2003. |
Germany | Social Democratic Party of Germany | SPD | Founding member. Withdrew in 2017. |
Greenland | Siumut | | Admitted as consultative member in 1986.[58] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Guatemala | Social Democratic Convergence[171] | CSD | Admitted as consultative member in 2003.[42][171] |
Haiti | Party of the National Congress of Democratic Movements | KONAKOM | Admitted as consultative member in 1992.[46] Promoted to full member in 1996.[47] |
| Struggling People's Organization | OPL | Admitted (as Lavalas Political Organisation) as observer member in 1996.[47] |
| Revolutionary Progressive Nationalist Party | PANPRA | Admitted as consultative member in 1989.[59] Promoted to full member in 1992.[46] |
Hungary | Social Democratic Party of Hungary | MSZDP | Member since 1990. Admitted as observer member in 1992. Promoted to consultative member in 1999. Promoted to full member in 2003. Delisted in 2020 due to inactivity |
Iceland | Social Democratic Party | A | Member since 1987.[172] FormedSocial Democratic Alliance in 2000. |
| Social Democratic Alliance | S | Withdrew in 2017. |
Iran | League of Iranian Socialists | | Joined in 1960.[173] It was dissolved in 1980s. |
Italy | Democratic Party of the Left | PDS | Admitted as full member in 1992.[46] Merged with others to formDemocrats of the Left in 1998. |
| Democrats of the Left[174] | DS | Full member since 1992 asDemocratic Party of the Left.[174] Merged with other movements to form theDemocratic Party in 2007. Listed as SI member until XXIV Congress in 2012. |
| Italian Socialist Party | PSI | Party dissolved in 1994 and succeeded by theItalian Socialists (who formed theItalian Democratic Socialists in 1998 and resumed as theItalian Socialist Party in 2007). |
| Italian Democratic Socialist Party | PSDI | Founding member. Party merged into theItalian Democratic Socialists in 1998 (renamed intoItalian Socialist Party in 2007). |
Japan | Democratic Socialist Party | DSP/Minsha-tō | Admitted as SI member in 1961.[175] Merged with non-socialist movements to form theNew Frontier Party in 1994. |
| Japan Socialist Party | JSP/Shakai-tō | Admitted as SI member in 1951.[91] Refounded as theSocial Democratic Party in 1996. |
Jordan | Jordanian Democratic Party of the Left | JDPL | Admitted as observer member in 2003.[42] |
Kyrgyzstan | Ata Meken Socialist Party[176] | | Admitted as observer member in 2008.[65] |
Latvia | Latvian Social Democratic Workers' Party[177] | LSDSP | Full member since 1994.[177] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
| Social Democratic Party "Harmony" | SDPS | Admitted as consultative member in June/July 2014.[66] Withdrew in 2017. |
North Macedonia | Social Democratic Union of Macedonia[178][179][180] | SDSM | Admitted as observer member in 1996.[47] Promoted to full member in 2003.[42][180] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Madagascar | Party for National Unity | VITM | Admitted as consultative member in 1989.[59] |
Malaysia | Democratic Action Party[181][136] | DAP | Full member since 1987.[136] Delisted in 2017.[181] |
Mexico | Party of the Democratic Revolution[182] | PRD | Admitted as full member in 1996.[47][182] |
Moldova | Social Democratic Party of Moldova | PSDM | Admitted as observer member in 1996.[47] |
Mongolia | Mongolian Social Democratic Party[106] | MSDP | Admitted as consultative member in 1992.[46][106] Promoted to full member in 1996.[47] Merged with others in 2000 to form theDemocratic Party. |
Namibia | Congress of Democrats | CoD | Admitted as consultative member in 2003.[42] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Netherlands | Labour Party[183] | PvdA | Decided to minimise involvement in SI in December 2012.[184] Delisted in December 2014. |
New Zealand | New Zealand Labour Party[133] | NZLP | Member since 1952.[133] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Nicaragua | Sandinista National Liberation Front | FSLN | Expelled in January 2019 because of violation of human rights during theNicaraguan protests |
Nigeria | All Progressives Congress[139] | APC | Admitted as consultative member in December 2014.[89] |
North Vietnam | Vietnamese Socialist Party[185] | | Consultative member between 1955 and 1969.[185] |
Norway | Labour Party[186][187] | DNA | Member since 1951.[187] Withdrew in 2016. |
Paraguay | Party for a Country of Solidarity[188] | PPS | Admitted as consultative member in 2003.[42] Promoted to full member in 2008.[65] |
| Revolutionary Febrerista Party[189][190] | PRF | Admitted as full member in the 1970s.[190] |
Philippines | Akbayan | | Admitted as consultative member in 2003.[42] |
Poland | Democratic Left Alliance[191][192] | SLD | Full member since 1996.[192] Withdrew in 2017. |
| Labour Union[193] | UP | Admitted as full member in 1996.[47][193] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
| Social Democracy of the Republic of Poland | SdRP | Admitted as full member in 1996.[47] Absorbed into theDemocratic Left Alliance in 1999. |
Romania | Democratic Party | PD | Admitted as consultative member in 1996.[47] Promoted to full member in 1999.[41] Merged with theLiberal Democratic Party to form theDemocratic Liberal Party. |
Russia | A Just Russia — Patriots — For Truth[194][195] | SRZP | Admitted as observer member in 2008.[65] Promoted to consultative member in 2010. Promoted to full member in 2012.[92][196] Expelled in March 2022 for its support for theRussian invasion of Ukraine.[197] |
Russia | Social Democratic Party of Russia | SDPR | Admitted as consultative member in 2003.[42] |
Saint Kitts and Nevis | Saint Kitts and Nevis Labour Party | SKNLP | Admitted as consultative member in 1992.[46] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Saint Lucia | Progressive Labour Party | | Expelled in 1992.[46] |
| Saint Lucia Labour Party | SLP | Admitted as consultative member in 1992.[46] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Saint Vincent and the Grenadines | Saint Vincent Labour Party | SVGLP | Admitted as consultative member in 1989.[59] Merged with theMovement for National Unity in 1994 to form theUnity Labour Party. |
| Unity Labour Party | ULP | Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Serbia | Democratic Party[198] | DS | Admitted as consultative member in 2003.[42] Promoted to full member in 2008.[65] |
| Social Democratic Party[198] | SDP | Admitted as consultative member in 2003.[42] Promoted to full member in 2008.[65] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Ceased to exist in 2009[198] |
Singapore | People's Action Party | PAP | Resigned in 1976 in response to theDutch Labour Party's charges of violations of human rights and detention of political prisoners without trial,[199] and DLP and theBritish Labour Party's charges of media censorship.[200][201] |
Slovakia | Party of the Democratic Left | SDĽ | Admitted as full member in 1996.[47] Merged withDirection – Social Democracy in 2005. |
| Social Democratic Party of Slovakia | SDSS | Admitted as full member in 1992.[46] Merged withDirection – Social Democracy in 2005. |
Slovenia | Slovenian Democratic Party | SDS | Admitted (as the Social Democratic Party of Slovenia) as observer member in 1992.[46] |
| Social Democrats[202] | SD | Admitted (asUnited List of Social Democrats) as full member in 1996.[47][202] Demoted to observer member in 2012 due to non-payment of membership fees.[36] Delisted in December 2014. |
Sweden | Swedish Social Democratic Party | SAP | Withdrew in March 2017.[203] |
Switzerland | Social Democratic Party of Switzerland[204] | SP/PS | Withdrew in 2017. |
Tanzania | Chama Cha Mapinduzi | CCM | Admitted as full member in 2013. |
Timor-Leste | Revolutionary Front for an Independent East Timor | FRETILIN | Admitted as consultative member in 2003.[42] |
Tunisia | Democratic Constitutional Rally[57] | RCD | Admitted as full member in 1989.[59] Full member since 1993.[57] Expelled in January 2011.[19] |
| Popular Unity Movement | MUP | Admitted as consultative member in 1989.[59] |
Turkey | Democratic Left Party | DSP | Admitted as consultative member in 1986.[58] Expelled in 1992.[46] |
| Democratic People's Party | DEHAP | Admitted as observer member in 2003.[42] Merged with the Democratic Society Movement to form theDemocratic Society Party which in turn was succeeded by thePeace and Democracy Party. |
| Social Democratic Populist Party | SHP | Admitted as consultative member in 1986.[58] Promoted to full member in 1989.[59] Merged with theRepublican People's Party in 1995. |
Ukraine | Socialist Party of Ukraine | SPU | Admitted as consultative member in 2003.[42] Expelled in July 2011.[205] |
United States | Democratic Socialists of America | DSA | Had been a member of SI since founding in 1982, withdrew in August 2017.[206] |
| Democratic Socialist Organizing Committee | DSOC | Member since 1976,[207] merged with theNew American Movement in 1982 to form the Democratic Socialists of America, which remained a member until 2017.[206] |
| Social Democrats, USA[202] | SDUSA | Member since 1972.[202] Withdrew in 2005. |
Uruguay | Party for the Government of the People | PGP | Admitted as consultative member in 1992.[46] Merged with theColorado Party in 1994. |
| Socialist Party of Uruguay[208] | PSUA | Admitted as full member in 1999.[41][208] Withdrew in 2017.[209] |
Venezuela | For Social Democracy | PODEMOS | Admitted as consultative member in 2008.[65] |
| Movement for Socialism | MAS | Admitted as consultative member in 2003.[42] |
Zambia | Patriotic Front | PF | Admitted as consultative member in 2013.[134] |
Zimbabwe | Movement for Democratic Change | MDC | Admitted as full member in 2008.[65] Delisted in 2017. |