Mueang Ubon Ratchathani (Thai: เมืองอุบลราชธานี, pronounced [mɯ̄aŋ ʔù.bōn râːt.tɕʰā.tʰāː.nīː]; Northeastern Thai: เมืองอุบลราชธานี, pronounced [mɯ᷇aŋ ʔǔ.bōn lâːt.sā.tʰa᷇ː.ni᷇ː]) is the capital district (amphoe mueang) of Ubon Ratchathani province, northeastern Thailand.

[1] Neighboring districts are (from the west clockwise) Khueang Nai, Muang Sam Sip, Lao Suea Kok, Don Mot Daeng, Sawang Wirawong, and Warin Chamrap of Ubon Ratchathani Province and Kanthararom of Sisaket province.

The city (thesaban nakhon) Ubon Ratchathani covers the entire tambon Nai Mueang.

Missing numbers are tambon which form the districts Don Mot Daeng and Lao Suea Kok.

The average annual high temperature in Ubon Ratchathani is 33 °C and the average annual low temperature is 22.1 °C with April being the hottest month and December being the coolest month.