After graduating from the Page Corps, Georgy entered service as a junior officer in the prestigious Hussar Regiment of the Imperial Life Guards.

He was subsequently posted to the Transcaspian Region after the Panjdeh Incident as part of the commission to fix the border of the Russian Empire with Afghanistan.

Orbeliani was promoted to major general in 1904 and assigned command of the Caucasian Cavalry Brigade, which played an active role in the Russo-Japanese War of 1904–1905 in Manchuria.

War correspondent Francis McCullagh commented on the diverse ethnic backgrounds of Orbeliani's Brigade in his book With the Cossacks, but also mentioned that most of his men could not communicate well with other units due to their lack of ability in the Russian language.

Orbeliani returned to active duty at the start of World War I, and was appointed supreme commander of medical evacuation services.