List of left-wing internationals

This is a list of socialist, communist, and anarchist, and other left-wing internationals. An "International" — such as, the "First International", the "Second International", or the "Socialist International" — may refer to a number of multi-national communist, radical liberal, socialist, or organized labour organizations, typically composed of national sections.

Progressive, social democratic, anti-capitalist, and socialist internationals

 * Socialist International (Democratic socialism, Social democracy)
 * Progressive Alliance (Progressivism)
 * Progressive International (Progressivism, Anti-capitalism)
 * International Peoples' Assembly (Progressivism, Anti-capitalism)
 * Horizon Federation (Libertarian socialism)

Classical Marxist and left-communist internationals
See also: Internationalist Communist Party and Communist Workers' Organisation
 * World Socialist Movement (Classical Marxism)
 * International Communist Current (Left communism)
 * International Communist Party (Left communism)
 * Internationalist Communist Tendency (Left communism)

Anarchist internationals

 * International of Anarchist Federations (Synthesis anarchism, Anarcho-communism)
 * International Workers' Association (Anarcho-syndicalism)
 * International Confederation of Labour (Anarcho-syndicalism)
 * anarkismo.net (Anarcho-communism, platformism)

Marxist–Leninist, Maoist and Hoxhaist internationals

 * International Meeting of Communist and Workers' Parties (Marxism–Leninism)
 * International Coordination of Revolutionary Parties and Organizations (Marxism–Leninism)
 * International Conference of Marxist–Leninist Parties and Organizations (Unity & Struggle) (Hoxhaism)
 * International Communist League (Marxism–Leninism–Maoism, Gonzalo Thought)

Trotskyist, Posadist and post-Trotskyist internationals

 * Committee for a Workers' International (Trotskyist) – claims to be refoundation of Committee for a Workers' International (1974)
 * Committee for Revolutionary International Regroupment (Trotskyist)
 * Fourth International (reunified) (Trotskyist)
 * International Committee of the Fourth International (Trotskyist)
 * International Committee of the Fourth International (Trotskyist) – associated with the Workers Revolutionary Party
 * International Communist League (Fourth Internationalist) (Trotskyist) – previously known as the International Spartacist Tendency
 * Revolutionary Communist International (Trotskyist) – previously known as the International Marxist Tendency and the Committee for a Marxist International
 * International Revolutionary Left (Trotskyist)
 * International Socialist Alternative (Trotskyist) – claims to be successor to Committee for a Workers' International (1974)
 * International Socialist Tendency (Post-Trotskyist)
 * Internationalist Communist Union (Trotskyist)
 * International Trotskyist Committee for the Political Regeneration of the Fourth International (Trotskyist)
 * International Workers League – Fourth International (Trotskyist)
 * International Workers' Unity – Fourth International (Trotskyist)
 * League for the Fifth International (Trotskyist)
 * League for the Fourth International (Trotskyist)
 * League for the Revolutionary Party – Communist Organization for the Fourth International (Trotskyist)
 * Organising Committee for the Reconstitution of the Fourth International (Trotskyist)
 * Trotskyist Fraction – Fourth International (Trotskyist)
 * Workers International to Rebuild the Fourth International (Trotskyist)
 * International Bolshevik Tendency (Trotskyist)
 * Bolshevik Tendency (Trotskyist)
 * International Leninist Trotskyist Tendency (Trotskyist)
 * Permanent Revolution Collective (Trotskyist)
 * International Leninist Trotskyist Fraction (Trotskyist)
 * Tendency for the Reconstruction of the Fourth International (Trotskyist)
 * Internationalist Trotskyist Nucleus-Fourth International (Trotskyist)
 * Fourth International Posadist (Posadist)
 * Liaison Committee for the Reconstruction of the Fourth International (Trotskyist)

Anti-imperialist internationals

 * International League of Peoples' Struggle
 * World Anti-Imperialist Platform

Green and ecologist internationals

 * World Ecological Parties (Ecologist)
 * Global Greens (Green)

Regional internationals

 * Communist Party of the Soviet Union (2001) (Marxism–Leninism, Post-Soviet states)
 * Coordination Committee of Maoist Parties and Organisations of South Asia (Maoism, South Asia)
 * European Anti-Capitalist Left (Democratic socialism, Europe)
 * Foro de São Paulo (Anti-neoliberalism, Latin America)
 * Now the People (Democratic socialism, Europe)
 * Party of the European Left (Socialism, Europe)
 * Permanent Conference of Political Parties of Latin America and the Caribbean (Leftism, Latin America and the Caribbean)
 * Union of Communist Parties – Communist Party of the Soviet Union (Marxism–Leninism, Post-Soviet states)
 * Conference of Communist and Worker's Parties of the Balkans (Marxism–Leninism, Balkans)
 * European Communist Action (Marxism–Leninism, Europe)

Defunct internationals

 * League of the Just (Christian communism, 1839–1847)
 * Communist League (Marxism, 1847–1852)
 * International Workingmen's Association ("First International") (Marxism, 1864–1876)
 * Anarchist St. Imier International, (Collectivist anarchism, 1872–1877)
 * International Working People's Association ("Black International") (Insurrectionary anarchism, Anarcho-collectivism, Anarcho-communism, 1881–1887)
 * Second International (Marxism, 1889–1916)
 * International Working Union of Socialist Parties ("2½ International") (Centrist Marxism, 1921–1923)
 * Communist International ("Third International") (Marxism–Leninism, 1919–1943)
 * Communist Workers' International (Council communism (1922–mid-1920s)
 * Labour and Socialist International (Socialism, 1923–1940)
 * International Revolutionary Marxist Centre ("2½ International") (Centrist Marxism, 1932–1940s)
 * Revolutionary Workers Ferment (Left communism, 1948–unknown)
 * Situationist International (Situationism, 1957–1971)
 * International League for the Reconstruction of the Fourth International (Trotskyism, 1973–1995)
 * Committee for a Workers' International (Trotskyism, 1974–2019)
 * Trotskyist International Liaison Committee (Trotskyism, 1979–1984)
 * Revolutionary Internationalist Movement (Marxism–Leninism–Maoism, 1984–2012)
 * International Communist Seminar (Marxism–Leninism, 1992–2014)
 * International Libertarian Solidarity (Anarchism, 2001–2005)
 * International Conference of Marxist–Leninist Parties and Organizations (International Newsletter) (Marxism–Leninism, Mao Zedong Thought, 1988–2017)
 * Coordinating Committee for the Refoundation of the Fourth International (Trotskyism, 2004–2017)
 * Initiative of Communist and Workers' Parties (Marxism–Leninism, Europe, 2013–2023)