The Russian Caucasus Army of World War I was the Russian field army that fought in the Caucasus Campaign and Persian Campaign of World War I. It was renowned for inflicting heavy casualties on the opposing forces of the Ottoman Empire, particularly at the Battle of Sarikamish. It was also known for its extremely diverse ethnic composition, consisting of units from throughout the Russian Empire and both soldiers and officers from the many ethnic communities settled since the 1877-78 Russo-Turkish War in the militarily administered Kars Oblast in the Russian Transcaucasus. These included Georgians, Caucasus Greeks, and Armenians - the latter in particular strongly represented among both the soldiers and senior officers - as well as ethnic Russians and Ukrainians.

The Caucasus campaign comprised armed conflicts between the Russian Empire and the Ottoman Empire, later including Armenia, Azerbaijan, Georgia, the Mountainous Republic of the Northern Caucasus, the German Empire, the Central Caspian Dictatorship, and the British Empire, as part of the Middle Eastern theatre during World War I. The Caucasus campaign extended from the South Caucasus to the Armenian Highlands region, reaching as far as Trabzon, Bitlis, Mush and Van. The land warfare was accompanied by naval engagements in the Black Sea.