The Duchy of Aragvi (Georgian: არაგვის საერისთავო, aragvis saeristavo) was an important fiefdom in medieval and early modern Georgia, strategically located in the upper Aragvi valley, in the foothills of the eastern Greater Caucasus crest, and ruled by a succession of eristavi ("dukes") from c. 1380 until being transferred to the royal crown in 1747.
The first known dukes of Aragvi belonged to the House of Shaburisdze which flourished in the 13th century. From this house, the duchy passed to those of Tumanisdze and, finally, in the 16th century, to the House of Sidamoni. This latter change of power took place sometime after 1569, when an obscure nobleman of the Sidamoni clan, with the aid of the dukes of the Ksani, massacred the Tumanisdze family and took control of their possessions. In the process of time, the tenure of a duke of Aragvi became hereditary, and the eristavi ranked as mtavari, one of the "undivided" princely houses of Georgia.
The dukes of Aragvi had their residences at Dusheti and Sioni, and the main fortress at Ananuri. Bodorna was their familial abbey and a burial ground. Their possessions extended from the main ridge of the Great Caucasus in the north to the left bank of the Mtkvari (Kura) in the south, and from the Liakhvi River in the west to the mountains of Alevi and Gremi in the east – which formed the watershed between the valleys of the Ksani and the Aragvi. As of the 1770 census, the duchy's population amounted to 3,300 households. The duchy controlled a vital road to the North Caucasus, which would later become the Georgian Military Road, as well as the fertile area of Bazaleti.