Ukrainian volunteer battalions mobilized as a response to the perceived state of weakness and unwillingness to counter rising separatism in spring 2014. The earliest of these volunteer units were later formalized into military, special police and paramilitary formations in a response to Russian military intervention in Ukraine. Most of the formations were formed by the government agencies of Ministry of Defence and Ministry of Internal Affairs; the minority are independent. As of September 2014, 37 volunteer battalions took active part in battles of the War in Donbass. It is widely believed that they are responsible for the most part of war crimes and atrocities committed by pro-Ukrainian forces. The majority of the battalion fighters are former Euromaidan activists, but their social background is highly diverse. They include students, military officers and even criminals. Nevertheless, they enjoy a high level of support in Ukrainian society ranked second among the most respected institutions in the country. However their close ties with Ukrainian oligarchs bring up a high risk of the volunteer formations becoming politicized or turning into private armies. Ordered to leave the front lines in 2015, the volunteer battalion phenomenon was largely over within a year of its beginning.
had established 56 special tasks patrol police units sized from company to battalion. After several reorganizations, this number shrunk to 33 units. The National Guard of Ukraine, subordinated to Ministry of Internal Affairs, had established several reserve battalions, among which were Donbas Battalion and General Kulchytskiy Battalion formed from volunteers and Maidan activists. According to Interior Minister Avakov, by mid-April 2016 205 service personnel of the ministry's volunteer battalions had been killed in action, National Guardsmen included.
had formed several battalions that are known as Ukrainian Volunteer Corps. In spring 2015 there were attempts to integrate Ukrainian Volunteer Corps into the Ukrainian Army or National Guard.
Battalion OUN
Battalion of "Organization of Ukrainian Nationalists" was operating in the area of Pisky, Donetsk. The battalion was disbanded in September 2019; as one of the last units comprised purely of volunteer soldiers.
Foreign fighters
Foreign fighters mainly from Belarus, Georgia and Russia have joined the volunteer battalions. They were joined by fighters from the United States, France, Germany, Norway, Sweden, Georgia, Poland, Spain, the Czech Republic, the United Kingdom, Croatia, Italy, Albania and Canada. Foreign fighters from Belarus and Russia have asked for Ukrainian citizenship fearing persecution at home. The Ukrainian parliament passed laws to simplify this for them. Nevertheless, foreign fighters from Belarus and Russia have complained that gaining this citizenship took too long.
Islamic battalions
According to New York Times, there are three volunteer Islamic battalions fighting for the Ukrainian side.
, originally named "Chechen battalion", it was set up in March 2014. It was later named after Chechnya’s first president and insurgent leader Dzhokhar Dudayev and it is based in Novomoskovsk in Dnipropetrovsk Oblast. As of late May 2015, the unit was in the process of being legalized as part of the Ukrainian Interior Ministry. Its Ukrainian members will join the Zoloti Borota Battalion, while its foreign members are expected to join army units under a bill enabling foreign fighters to get Ukrainian citizenship. Most of the members are ethnic Ukrainians, but there are also Chechens from European countries as well as from Chechnya and it also includes other Muslims like Azeris, Ingush and Tatars, as well as Georgians. The battalion "views the war as part of a broader struggle against Russian imperialism and the Kadyrov regime". The battalion specializes in subversion and countering the subversive groups.
Another Chechen battalion, named after Shah Mansur, has been reported defending the front line near Mariupol in 2015. It was created by former Dzhokhar Dudayev Battalion members. The battalion was disbanded in September 2019; as one of the last units comprised purely of volunteer soldiers.
