Gran Chaco is a province in the eastern parts of the Bolivian department Tarija. The province voted to become an autonomous region on 6 December 2009.
Gran Chaco province is one of six provinces in the Tarija Department. It is located between 21° 00' and 22° 17' south and between 62° 16' and 64° 18' west.
The province borders Chuquisaca Department in the north, Burnet O'Connor Province in the north-west, Aniceto Arce Province in the south-west, Argentina in the south, and Paraguay in the east.
The province extends over 200 km from north to south, and 200 km from east to west.