The Treaty of Alexandropol was a pivotal peace agreement signed in December 1920, concluding the Turkish–Armenian War that erupted shortly after the collapse of the Ottoman Empire and the tumultuous aftermath of World War I. The war stemmed from various territorial disputes, particularly over regions that both Armenia and Turkey claimed, including areas of Eastern Anatolia, where many ethnic Armenians resided. The signing of the treaty took place in the city of Alexandropol, present-day Gyumri in Armenia, and was facilitated by significant military pressures from Turkish forces, led by Mustafa Kemal Atatürk, against Armenian defenses.

One of the most critical aspects of the treaty was its imposition of territorial losses on Armenia. The treaty forced Armenia to cede a significant portion of its territory to Turkey, directing Armenia’s borders toward a much smaller area than originally envisioned post-war. Furthermore, the treaty included provisions that called for demilitarization and a modified military presence in the region, which limited Armenia's ability to defend its borders.

The Treaty of Alexandropol not only resolved the immediate military conflict but also set the stage for further geopolitical shifts in the region. It was seen as a reflection of the prevailing power dynamics of the period, especially the influence and ambitions of emerging nationalist movements. Nations and populations affected by these new borders would face long-lasting consequences, shaping interactions in the South Caucasus for decades to follow.