Ubon Ratchathani is one of the north-eastern provinces of Thailand, and the country's easternmost. Ubon is about 600 km away from Bangkok.

Neighboring Provinces are (from west clockwise) Sisaket, Yasothon and Amnat Charoen. To the north and east it borders Salavan and Champasak of Laos, to the south Preah Vihear of Cambodia.