There are no diplomatic relations between Armenia and Azerbaijan. The two neighboring states had formal governmental relations between 1918 and 1921, during their brief independence from the collapsed Russian Empire, as the First Republic of Armenia and the Democratic Republic of Azerbaijan; these relations existed from the period after the Russian Revolution until they were occupied and annexed by the Soviet Union, becoming the constituent republics of Soviet Armenia and Soviet Azerbaijan. Due to the five wars waged by the countries in the past century—one from 1918 to 1921, another from 1988 to 1994, and the most recent in 2016, 2020 and 2023—the two have had strained relations. In the wake of hostilities, social memory of Soviet-era cohabitation is widely repressed through censorship and stigmatization.

The First Republic of Armenia, officially known at the time of its existence as the Republic of Armenia, was an independent Armenian state that existed from May 1918 to 2 December 1920 in the Armenian-populated territories of the former Russian Empire known as Eastern or Russian Armenia. The republic was established in May 1918, with its capital in the city of Yerevan, after the dissolution of the short-lived Transcaucasian Democratic Federative Republic. It was the first Armenian state since the Middle Ages.