| Official Name: | Nam Khun |
| Native Name: | น้ำขุ่น |
| Native Name Lang: | th |
| Settlement Type: | District |
| Subdivision Type: | Country |
| Subdivision Name: | Thailand |
| Subdivision Type1: | Province |
| Subdivision Name1: | Ubon Ratchathani |
| Subdivision Type2: | Seat |
| Subdivision Name2: | Ta Kao |
| Subdivision Type3: | Tambon |
| Subdivision Type4: | Muban |
| Established Title: | District established |
| Population Total: | 30587 |
| Population As Of: | 2005 |
| Blank Name Sec1: | Postal code |
| Blank Info Sec1: | 34260 |
| Blank Name Sec2: | Geocode |
| Blank Info Sec2: | 3433 |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Coordinates: | 14.5833°N 104.925°W |
Nam Khun (Thai: น้ำขุ่น, in Thai pronounced as /náːm kʰùn/) is a district (amphoe) in the southwestern part of Ubon Ratchathani province, northeastern Thailand. The name of the district translates to 'muddy water'.
The area of Nam Khun was originally part of Nam Yuen district. The government created the minor district (king amphoe) on 15 July 1996.[1]
On 15 May 2007, all of 81 minor districts were upgraded to full districts.[2] On 24 August the upgrade became official.[3]
The district is bounded in the south by the Dangrek Range.
Neighboring districts are (from the west clockwise) Kantharalak of Sisaket province; Thung Si Udom, Det Udom and Nam Yuen of Ubon Ratchathani; and Preah Vihear of Cambodia.
The district is divided into four sub-districts (tambons), which are further subdivided into 49 villages (mubans). There are no municipal (thesaban) areas, and four tambon administrative organizations (TAO).
| No. | Name | Thai name | Villages | Pop. | ||
|---|---|---|---|---|---|---|
| 1. | Ta Kao | ตาเกา | 12 | 8,936 | ||
| 2. | Phaibun | ไพบูลย์ | 14 | 7,316 | ||
| 3. | Khilek | ขี้เหล็ก | 13 | 7,840 | ||
| 4. | Khok Sa-at | โคกสะอาด | 10 | 6,495 |