The Treaty of Alexandropol was a peace treaty between the First Republic of Armenia and the Grand National Assembly of Turkey. The treaty formally ended Turkey's invasion of Armenia that had begun on 12 September 1920.
It was signed by the Armenian Foreign Minister Alexander Khatisyan in the early hours of 3 December 1920; however, the previous day, the Armenian government in Yerevan had resigned and transferred power to a Soviet government and so Khatisyan was no longer acting on behalf of the government of Armenia, and the treaty was invalid.
The treaty required Armenia to relinquish claims to Western Armenia, cede over half of its territory to Turkey while also transferring Nakhchivan to Azerbaijan, and accept conditions that reduced Armenia to the status of a Turkish client state.