List of Trotskyist internationals

This is a list of Trotskyist internationals. It includes all of the many political internationals which self-identify as Trotskyist.

Of the organizations listed, two claim to be the original Fourth International founded in 1938: the reunified Fourth International (USFI) and the International Committee of the Fourth International (ICFI). The Fourth International split into two factions 1953 over the question of historic perspective, with the International Secretariat (ISFI) turning in favour of deep entryism and supporting petty-bourgeois nationalist movements in less developed countries, and the International Committee (ICFI) upholding the need to form revolutionary parties. The factions reunited in 1963 resulting in the formation of reunified Fourth International (USFI), while parts of the ICFI did not. Both the USFI and ICFI went on to fragment further, giving rise to several new internationals.

Certain organizations which claim to be Trotskyist make no attempt to claim any relationship to the Fourth International in an organizational sense and argue that it no longer exists. Some claim to represent a continuity from the Fourth International or to have re-established it: for example the Fourth International (ICR) International Centre/Center of Reconstruction, also known as the FI (La Verité), also calls itself the "Fourth International".

The various organizations listed here range in size from those having thousands of adherents in dozens of countries to tendencies which can barely claim a dozen members in three or four countries.

List of internationals
The largest internationals in terms of membership are indicated in bold.

Internationals that emerged from the Fourth International (USFI)

 * International Workers League – Fourth International (IWL-FI), founded by former members of the USFI in 1982.
 * Trotskyist Fraction – Fourth International (TF-FI), founded by expelled members of the IWL-FI in 1988
 * International Workers' Unity – Fourth International (IWU-FI), split from IWL-FI in 1997.
 * International Leninist Trotskyist Fraction (ILTF), split from the TF-FI in 1998.
 * Tendency for the Reconstruction of the Fourth International, formed by expelled members of the TF-FI in 2006.
 * Committee for Revolutionary International Regroupment (CRIR), founded by groups originating from the USFI and IWL-FI
 * Committee for a Workers' International (CWI) - claims to be refoundation of the defunct Committee for a Workers' International (1974), which was formed by expelled members of the USFI in 1965, after 2019 split.
 * Revolutionary Communist International, split from CWI in 1992. Previously named International Marxist Tendency (IMT) (2004–2024), and the Committee for a Marxist International (1992–2004)
 * International Revolutionary Left (IRL), split from CWI in 2019.
 * International Socialist Alternative, claims to be successor to the defunct Committee for a Workers' International (1974) after 2019 split.
 * Internationalist Standpoint (IS), split from International Socialist Alternative in 2022.
 * International Socialist Tendency (IST), founded by expelled members of the original Fourth International in the 1950s
 * League for the Fifth International (L5I), founded by expelled members of the IST.
 * Revolutionary Communist International Tendency (RCIT), founded by former members of the IST and L5I.
 * Internationalist Trotskyist Nucleus-Fourth International, founded as a "public faction" of the ILTF, and split from the RCIT.
 * Liaison Committee for the Reconstruction of the Fourth International (CERCI), founded by the Bolivian party POR which broke off with the original Fourth International in the 1950s.

Internationals that emerged from the International Committee of the Fourth International (ICFI)

 * International Communist League (Fourth Internationalist) (ICL-FI), previously the international Spartacist tendency which split from the ICFI in 1966.
 * International Bolshevik Tendency (IBT) formed by expelled members of the international Spartacist tendency in 1982.
 * Bolshevik Tendency, split from IBT in 2018.
 * League for the Fourth International (LFI), formed by expelled members of the ICL-FI in 1996.
 * Organising Committee for the Reconstitution of the Fourth International (OCRFI), split from the defunct Fourth International (ICR) in 2016. The latter was formed after a split from the ICFI in 1972.
 * International Trotskyist Committee (ITC), founded by former members of the defunct Trotskyist International Liaison Committee in 1984. The latter was founded by expelled members of the ICFI in 1974.
 * Liaison Committee for the Fourth International, founded by former members of the ITC.

Others

 * Internationalist Communist Union (ICU)
 * Permanent Revolution Collective

Defunct

 * Committee for a Workers' International (CWI), 1974–2019 – split into Committee for a Workers' International (Refounded) and International Socialist Alternative
 * Coordinating Committee for the Refoundation of the Fourth International (CRFI)
 * International League for the Reconstruction of the Fourth International (ILRFI), 1976–1995
 * Fourth International Posadist
 * Workers International to Rebuild the Fourth International (WIRFI)
 * International Revolutionary Marxist Tendency (TMRI), 1965–1992
 * Permanent Revolution
 * Revolutionary Workers Ferment (Fomento Obrero Revolucionario, FOR)
 * Trotskyist International Liaison Committee, 1979–1984
 * Tendencia Cuartainternacionalista
 * Fourth International (ICR), also called FI (La Verité) or FI (International Secretariat) 1981–2015
 * Socialist Network (Post-Trotskyist, split from IMT)