Det Udom () is a district (amphoe) in the southern part of Ubon Ratchathani province, in northeastern Thailand.
Geography Neighboring districts are (from the northwest clockwise) Samrong, Warin Chamrap, Na Yia, Phibun Mangsahan, Buntharik, Na Chaluai, Nam Yuen, Nam Khun, Thung Si Udom of Ubon Ratchathani Province, and Benchalak of Sisaket province
Administration The district is divided into 16 sub-districts (tambons), which are further subdivided into 229 villages (mubans). Mueang Det is a town (thesaban mueang) covering parts of the same-named tambon. There are also three townships (thesaban tambons): Na Suang and Bua Ngam each cover parts of the same-named tambon, and Kut Prathai covers tambon Kut Prathai. There are a further 10 tambon administrative organizations (TAO). No. Name Thai name Villages Pop.1.Mueang Detเมืองเดช3132,9192.Na Suangนาส่วง128,9434.Na Charoenนาเจริญ116,9636.Thung Thoengทุ่งเทิง158,1808.Som Sa-atสมสะอาด1210,4139.Kut Prathaiกุดประทาย2012,61310.Top Huตบหู2111,40611.Klangกลาง1714,26912.Kaengแก้ง117,86613.Tha Pho Siท่าโพธิ์ศรี106,47715.Bua Ngamบัวงาม1611,95316.Kham Khrangคำครั่ง106,18017.Na Krasaengนากระแซง1213,02020.Phon Ngamโพนงาม128,58521.Pa Mongป่าโมง104,53523.Non Sombunโนนสมบูรณ์95,574 Missing numbers are tambons which now form Districts Na Yia and Thung Si Udom.