The Vilna offensive was a campaign of the Polish–Soviet War of 1919–1921. The Polish army launched an offensive on April 16, 1919, to take Vilnius (Polish: Wilno) from the Red Army. After three days of street fighting from April 19–21, the city was captured by Polish forces, causing the Red Army to retreat. During the offensive, the Poles also succeeded in securing the nearby cities of Lida, Pinsk, Navahrudak, and Baranovichi.

The Red Army launched a series of counterattacks in late April, all of which ended in failure. The Soviets briefly recaptured the city a year later, in spring 1920, when the Polish army was retreating along the entire front. In the aftermath, the Vilna offensive would cause much turmoil on the political scene in Poland and abroad.

Soviet Russia, while at the time publicly supporting Polish and Lithuanian independence, sponsored communist agitators working against the government of the Second Polish Republic, and considered that its eastern borders should approximate those of the defunct Congress Poland. Poles and Lithuanians, on the other hand, inspired by memories of the greatness of the erstwhile Grand Duchy of Lithuania, part of the Polish–Lithuanian Commonwealth, saw their borders as lying much farther east. The leader of the Polish forces, Józef Piłsudski, discerned an opportunity for regaining territories that were once the part of the Polish–Lithuanian Commonwealth, and since then were the part of the Russian Empire, shaken by the 1917 Revolution and the ongoing Russian Civil War.