Non Sa-at (Thai: โนนสะอาด, pronounced [nōːn sāʔàːt]) is a district (amphoe) in the southern part of Udon Thani province, northeastern Thailand.

Neighboring districts are (from the north clockwise) Nong Saeng and Kumphawapi of Udon Thani Province, Kranuan, Nam Phong, and Khao Suan Kwang of Khon Kaen province.

The minor district (king amphoe) was established on 21 January 1974, when the three tambons, Non Sa-at, Pho Si Samran, and Bung Kaeo, were split off from Kumphawapi district. It was upgraded to a full district on 12 April 1977.

The district is divided into six sub-districts (tambons), which are further subdivided into 63 villages (mubans). Non Sa-at is a township (thesaban tambon) which covers parts of tambon Non Sa-at. There are a further six tambon administrative organizations (TAO).

No.	Name	Thai name	Villages	Pop.
1.	Non Sa-at	โนนสะอาด	9	8,666
2.	Bung Kaeo	บุ่งแก้ว	12	10,746
3.	Pho Si Samran	โพธิ์ศรีสำราญ	9	8,164
4.	Thom Na Ngam	ทมนางาม	10	7,077
5.	Nong Kung Si	หนองกุงศรี	11	6,813
6.	Khok Klang	โคกกลาง	12	6,993

Non Sa-at is a source for growing mulberries and raising sericulture to produce good quality Thai silk.

• amphoe.com