Don Tan (Thai: ดอนตาล, pronounced [dɔ̄ːn tāːn]) is the southeasternmost district (amphoe) of Mukdahan province, northeastern Thailand.

Originally Don Tan was a tambon of Mukdahan district, Nakhon Phanom province. Don Tan was upgraded to a minor district (king amphoe) in 1963, which was further upgraded to a full district in 1974. When the government established Mukdahan Province in 1982, Don Tan district was assigned to be a district of the new province.

Neighboring districts are (from the southeast clockwise) Chanuman of Amnat Charoen province; Loeng Nok Tha of Yasothon province; Nikhom Kham Soi and Mueang Mukdahan of Mukdahan Province. To the east across the Mekong River is the Laotian province of Savannakhet.

The important water resource is the Mekong River.

The district is divided into seven sub-districts (tambons), which are further subdivided into 62 villages (mubans). Don Tan is a sub-district municipality (thesaban tambon) which covers parts of the tambon Don Tan. There are a further seven tambon administrative organizations (TAO).

No.	Name	Thai	Villages	Pop.
1.	Don Tan	ดอนตาล	12	7,013
2.	Pho Sai	โพธิ์ไทร	07	4,686
3.	Pa Rai	ป่าไร่	11	8,609
4.	Lao Mi	เหล่าหมี	09	6,595
5.	Ban Bak	บ้านบาก	07	5,432
6.	Na Sameng	นาสะเม็ง	09	7,047
7.	Ban Kaeng	บ้านแก้ง	07	2,833

• amphoe.com (Thai)