The city was founded in the late 18

The city was founded in the late 18th century by Thao Kham Phong, descendant of Phra Wo and Phra Ta, who escaped from King Siribunsan of Vientiane into Siam Kingdom during the reign of King Taksin the Great. Later Thao Kham Phong was appointed to be “Phra Pathum Wongsa" The first ruler of Ubon Ratchathani. In 1792 Ubon Ratchathani became a province, and was also the administrative center of the monthon Isan. Until 1972 the Ubon Ratchathani Province was the largest province of Thailand by area. Yasothon province was split off from Ubon Ratchathani Province in 1972, followed by Amnat Charoen province in 1993.
Before it became a province. Ubon Ratchathani was the administrative center of the monthon Isan, of which monthon Ubon was split off. In 1925 it became part of monthon Nakhon Ratchasima, with the abolishment of the monthon in 1933 the province became a first level subdivision of the country.