| Official Name: | Phon Na Kaeo |
| Native Name: | โพนนาแก้ว |
| Native Name Lang: | th |
| Settlement Type: | District |
| Subdivision Type: | Country |
| Subdivision Name: |  Thailand |
| Subdivision Type1: | Province |
| Subdivision Name1: | Sakon Nakhon |
| Subdivision Type2: | Seat |
| Subdivision Name2: | Na Kaeo |
| Subdivision Type3: | Tambon |
| Subdivision Type4: | Muban |
| Established Title: | District established |
| Population Total: | 35579 |
| Population As Of: | 2005 |
| Blank Name Sec1: | Postal code |
| Blank Info Sec1: | 47230 |
| Blank Name Sec2: | Geocode |
| Blank Info Sec2: | 4717 |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Coordinates: | 17.2211°N 104.29°W |
Phon Na Kaeo (Thai: โพนนาแก้ว, in Thai pronounced as /pʰōːn nāː kɛ̂ːw/) is a district (amphoe) of Sakon Nakhon province, northeast Thailand.
The minor district (king amphoe) was created on 1 April 1991, when the four tambons Ban Phon, Na Kaeo, Na Tong Watthana, and Ban Paen were split off from Mueang Sakon Nakhon district.[1] It was upgraded to a full district on 5 December 1996.[2]
Neighboring districts are (from the south clockwise) Khok Si Suphan, Mueang Sakon Nakhon and Kusuman of Sakon Nakhon Province, Pla Pak, Huai Phueng and Wang Yang of Nakhon Phanom province.
The district is divided into five sub-districts (tambons), which are further subdivided into 48 villages (mubans). There are no municipal (thesaban) areas, and a further five tambon administrative organizations.
| No. | Name | Thai name | Villages | Pop. | ||
|---|---|---|---|---|---|---|
| 1. | Ban Phon | บ้านโพน | 8 | 6,378 | ||
| 2. | Na Kaeo | นาแก้ว | 12 | 10,848 | ||
| 3. | Na Tong Watthana | นาตงวัฒนา | 11 | 6,553 | ||
| 4. | Ban Paen | บ้านแป้น | 10 | 6,957 | ||
| 5. | Chiang Sue | เชียงสือ | 7 | 4,843 |