The Transcaucasian Democratic Federative Republic (TDFR, Закавказская демократическая Федеративная Республика (ЗКДФР), Zakavkazskaya Demokraticheskaya Federativnaya Respublika (ZKDFR); also known as the Transcaucasian Federation) (February 1918 – May 1918) was a short-lived state composed of the modern-day countries of Armenia, Azerbaijan, and Georgia in the Caucasus Mountain Range.
After the February Revolution, the Russian Provisional Government installed the Special Transcaucasian Committee (особый Закавказский Комитет (ОЗАКОМ), osobyy Zakavkazskiy Komitet (OZAKOM)) to govern the area. After the October Revolution it was replaced by the Transcaucasian Republic and Transcaucasian Commissariat, in its turn replaced by the TCDFR.
The Transcaucasian Sejm was convened on February 10, 1918, and was chaired by a Georgian Menshevik Nikolay Chkheidze. The Sejm proclaimed the Transcaucasus an independent democratic federative republic on February 24. The federation dissolved when Georgia declared its independence on May 26. Armenia and Azerbaijan followed on May 28.