The Volunteer Army (Polish: Armia Ochotnicza) was a military formation of the Polish Army, created at the height of the Polish–Soviet War. It was formed by the Council of National Defense on July 1, 1920. Composed entirely of volunteers, the formation did not enter combat as a single entity. Instead, its regiments were attached to other armies or used to replenish the manpower of battle-weary divisions. The army was commanded by Gen. Józef Haller.
By the end of September 1920, 105,714 men volunteered for service. Out of them, sixteen regiments of infantry and seven of cavalry were created, in addition to other units. Out of the infantry regiments, only six took part in actual combat; the rest were used as reserves. Following the armistice, most of the volunteers were demobilised.
In late May 1920, after Polish forces had entered Kiev (see Kiev Offensive (1920)), the Red Army began its offensive, which resulted in fast advancing of the Soviets and retreat of Polish forces. In June 1920 in Warsaw, the government of Leopold Skulski was dismissed, and the new cabinet of Wladyslaw Grabski was not created until June 23. The new Prime Minister, well aware of the disastrous situation, created Council of National Defense (July 1, 1920), which was authorized to take decisions regarding the war.