
The International Freedom Battalion, commonly abbreviated as IFB or EÖT, is an armed group consisting of leftist foreign fighters fighting for the People's Protection Units in the Syrian Civil War in support of the Rojava Revolution and against the Islamic State of Iraq and the Levant, the Turkish Armed Forces, and the Turkish-backed Free Syrian Army. The formation of the IFB was announced in June 2015 in Serê Kaniyê. Inspiration for the group came from the International Brigades of the Spanish Civil War. The political ideologies of the fighters include Marxism–Leninism, Hoxhaism, Maoism, and anarcho-communism.

Devrimci Karargâh was a nominally Marxist-Leninist organization in Turkey.
Haukur Hilmarsson was an Icelandic anarchist and political activist. He played a crucial role in initiating a movement for the rights of refugees in Iceland. He rose to prominence during the 2009 Icelandic financial crisis protests after climbing to the roof of the house of the Icelandic parliament, Alþingishúsið, and hoisting the flag of the Bónus supermarket chain on the building's flagpole. His arrest two weeks later resulted in an attempt by a crowd of protesters to storm the Icelandic Police headquarters in downtown Reykjavík where Haukur was held and from where he was subsequently released.

The International Revolutionary People's Guerrilla Forces (IRPGF) was a collective of anarchist fighters from around the world. Its formation was announced on 31 March 2017. According to the group, their goals were to defend the social revolution in Rojava in northern Syria, and spread anarchism. The group announced its dissolution on 24 September 2018.

Marxist–Leninist Armed Propaganda Unit, known fully as People's Liberation Party-Front of Turkey/Marxist–Leninist Armed Propaganda Unit (THKP-C/MLSPB) is a Marxist–Leninist organization from Turkey. The group is a split from the People's Liberation Party-Front of Turkey. The group was among the founding members of the Peoples' United Revolutionary Movement, formed in March 2016, with the Kurdistan Workers' Party and 7 other Marxist–Leninist organizations.

The Marxist-Leninist Communist Party is an underground Hoxhaist communist party in Turkey. It was founded in 1994, and has been involved in the Rojava conflict since 2012.

Marxist-Leninist Party is a Marxist-Leninist and Hoxhaist political party operating in Spain, officially registered since 2014. Currently (2015) the party has a presence in the Basque Country, Majorca, Valencia, Catalonia, Andalusia, Galicia and Madrid.

Lorenzo Orsetti, also known as Orso and Tekoşer Piling, was an Italian anarcho-communist and antifascist from Florence who fought with the Kurdish People's Protection Units (YPG) in Syria.

Nubar Ozanyan was a Turkish-born Armenian radical communist revolutionary, who served as a commander in the militant Communist Party of Turkey/Marxist–Leninist (TKP/ML). Fighting in several conflicts for the group, he eventually died in combat against the Islamic State of Iraq and the Levant during the Battle of Raqqa.

The Revolutionary Communard Party is a left-wing political organisation founded on 4 February 2016, following the merger of the Liberation Movement and the Turkish Revolutionary Party.

The Revolutionary Union for Internationalist Solidarity, also known as RUIS is an anarchist military unit, part of the International Freedom Battalion involved in the Syrian Civil War. It was founded in 2015 and is composed mostly of Greek volunteers. In 2017, Greek authorities estimated the size of the group at five or six.

The Queer Insurrection and Liberation Army (TQILA) was a queer anarchist armed group and subunit of the International Revolutionary People's Guerrilla Forces formed on 24 July 2017 by LGBT members of the IRPGF. Its formation was announced from Raqqa City along with a statement explaining the purposes of its formation; the systematic persecution of LGBT people by ISIL was highlighted as a significant motivation for the creation of the group. TQILA is reported to be the first LGBT unit to fight against the Islamic State of Iraq and the Levant, and apparently the first LGBT militia in the Middle East.

The United Freedom Forces is a joint expatriate militia of several revolutionary socialist organizations from Turkey, most notably the Revolutionary Communard Party (DKP), active in the Rojava conflict of the Syrian Civil War.