| Official Name: | Nong Phai |
| Native Name: | หนองไผ่ |
| Native Name Lang: | th |
| Settlement Type: | District |
| Subdivision Type: | Country |
| Subdivision Name: | Thailand |
| Subdivision Type1: | Province |
| Subdivision Name1: | Phetchabun |
| Subdivision Type2: | Seat |
| Subdivision Type3: | Tambon |
| Subdivision Type4: | Muban |
| Established Title: | District established |
| Population Total: | 115832 |
| Population As Of: | 2000 |
| Blank Name Sec1: | Postal code |
| Blank Info Sec1: | 67140 |
| Blank Name Sec2: | Geocode |
| Blank Info Sec2: | 6707 |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Coordinates: | 15.9903°N 101.0625°W |
Nong Phai (in Thai pronounced as /nɔ̌ːŋ pʰàj/) is a district (amphoe) in the southern part of Phetchabun province, northern Thailand.
The area was created as a minor district (king amphoe) in 1961. It was upgraded to a full district in 1963.
Neighboring district are (from the east clockwise) Nong Bua Daeng and Phakdi Chumphon of Chaiyaphum province, Bueng Sam Phan, Chon Daen and Mueang Phetchabun of Phetchabun Province.
The main water resource is the Pa Sak River.
The district is divided into 13 sub-districts (tambons), which are further subdivided into 135 villages (mubans). There are six townships (thesaban tambons) in the district: Ban Phot, Bo Thai, Bua Watthana, Chaliang Thong, Na Chaliang, and Nong Phai, each covering parts of the same-named tambon. There are a further 13 tambon administrative organizations (TAO).
| 1. | Kong Thun | กองทูล | ||
| 2. | Na Chaliang | นาเฉลียง | ||
| 3. | Ban Phot | บ้านโภชน์ | ||
| 4. | Tha Daeng | ท่าแดง | ||
| 5. | Phet Lakhon | เพชรละคร | ||
| 6. | Bo Thai | บ่อไทย | ||
| 7. | Huai Pong | ห้วยโป่ง | ||
| 8. | Wang Tha Di | วังท่าดี | ||
| 9. | Bua Watthana | บัววัฒนา | ||
| 10. | Nong Phai | หนองไผ่ | ||
| 11. | Wang Bot | วังโบสถ์ | ||
| 12. | Yang Ngam | ยางงาม | ||
| 13. | Tha Duang | ท่าด้วง |