The Tambov Rebellion of 1920–1921 was one of the largest and best-organized peasant rebellions challenging the Bolshevik government during the Russian Civil War. The uprising took place in the territories of the modern Tambov Oblast and part of the Voronezh Oblast, less than 480 kilometres (300 mi) southeast of Moscow.

In Soviet historiography, the rebellion was referred to as the Antonovschina ("Antonov's mutiny"), so named after Alexander Antonov, a former official of the Socialist Revolutionary Party, who opposed the government of the Bolsheviks. It began in August 1920 with resistance to the forced confiscation of grain and developed into a guerrilla war against the Red Army, Cheka units and the Soviet Russian authorities. The bulk of the peasant army was destroyed in the summer of 1921, smaller groups continued until the following year. It is estimated that around 100,000 people were arrested and around 15,000 killed during the suppression of the uprising. The Red Army used chemical weapons to fight the peasants.