The Red Army invasion of Azerbaijan, also known as the Sovietization or Soviet invasion of Azerbaijan, took place in April 1920. It was a military campaign conducted by the 11th Army of Soviet Russia with the aim of installing a new Soviet government in the Azerbaijan Democratic Republic. This invasion occurred simultaneously with an anti-government insurrection organized by local Azerbaijani Bolsheviks in the capital city of Baku. As a result of the invasion, the Azerbaijan Democratic Republic was dissolved, and the Azerbaijan Soviet Socialist Republic was established.

The 11th Army was a field army of the Red Army during the Russian Civil War, which fought on the Caspian-Caucasian Front. It took a prominent part in the sovietization of the three republics of the southern Caucasus in 1920–21, when Azerbaijan, Armenia, and Georgia were brought within the orbit of Soviet Russia.