Since the 10th century, Ubon Ratchathani, or simply Ubon, was part of the Khmer Empire until the Ayutthaya Kingdom conquered it. Towards the end of the 18th century, Laotians immigrated to the northern banks of the Mun River and founded the provincial capital. The Laotian influence is evident in the architectural structures of some of the city’s religious buildings. During the Vietnam War, Ubon encountered an expansive growth due to it's proximity to an American air base.

Today, the province is the largest and one of the most important provinces in northeastern Thailand. It is the major tourist attraction of the lower Isan and is located 629 Kilometers from Bangkok. Because of the large number of important temples located throughout the city, Ubon is a place of pilgrimage at the beginning of Buddhist Lent.  Numerous attractions in and around Ubon, and the many festivals and holidays that are celebrated in Ubon give it a unique cultural flair all it's own. The province is bordered on the East by the Mekong River and provides superb scenic views of Cambodia.

The province covers 15,517 square Kilometers and consists of the following districts: Muang, Warin Chamrap, Det Udom, Buntharik, Na Chaluai, Nam Yuen, Phibun Mangsahan, Khong Chiam, Si Muang Mai, Trakan Phuet Phon, Khemarat, Mung Sam Sip, Khueang Nai, Kut Khaopun, Tan Sum, Pho Sai, Samrong, Sirindhorn, Don Mot Daeng, Thung Si Udom, Na Yia, Na Tan, Lao Suea Kok, Sawang Wirawong and Nam Khun.