| Official Name: | Phon Phisai |
| Native Name: | โพนพิสัย |
| Native Name Lang: | th |
| Settlement Type: | District |
| Subdivision Type: | Country |
| Subdivision Name: | Thailand |
| Subdivision Type1: | Province |
| Subdivision Name1: | Nong Khai |
| Subdivision Type2: | Seat |
| Population Total: | 96580 |
| Population As Of: | 2008 |
| Blank Name Sec1: | Postal code |
| Blank Info Sec1: | 43120 |
| Blank Name Sec2: | Geocode |
| Blank Info Sec2: | 4305 |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Coordinates: | 18.0219°N 103.0772°W |
Phon Phisai (Thai: โพนพิสัย, in Thai pronounced as /pʰōːn pʰíʔ.sǎj/; โพนพิสัย, in Lao pronounced as /pʰo᷇ːn pʰìʔ.sǎj/) is a district (amphoe) in Nong Khai province, northeastern Thailand.
The district was originally part of Mueang Phon Phaeng, now part of Rattanawapi district. In 1906 it was established as a district.
Neighboring districts are (from the east clockwise) Rattanawapi and Fao Rai of Nong Khai Province; Ban Dung, Sang Khom, and Phen of Udon Thani province; and Mueang Nong Khai of Nong Khai. To the north across the Mekong River are the Laotian Vientiane Prefecture and Bolikhamxai province.
The district is divided into 11 sub-districts (tambons), which are further subdivided into 151 villages (mubans). Chumphon is a sub-district municipality (thesaban tambon) which covers parts of tambon Chumphon. There are a further 11 tambon administrative organizations (TAO).
| No. | Name | Thai | Villages | Pop.[1] | |
|---|---|---|---|---|---|
| 1. | Chumphon | จุมพล | 24 | 19,738 | |
| 2. | Wat Luang | วัดหลวง | 16 | 9,200 | |
| 3. | Kut Bong | กุดบง | 14 | 8,681 | |
| 4. | Chum Chang | ชุมช้าง | 19 | 9,498 | |
| 6. | Thung Luang | ทุ่งหลวง | 12 | 5,172 | |
| 7. | Lao Tang Kham | เหล่าต่างคำ | 13 | 6,376 | |
| 8. | Na Nang | นาหนัง | 16 | 11,129 | |
| 9. | Soem | เซิม | 10 | 7,426 | |
| 13. | Ban Pho | บ้านโพธิ์ | 12 | 10,281 | |
| 21. | Ban Phue | บ้านผือ | 7 | 5,440 | |
| 22. | Sang Nang Khao | สร้างนางขาว | 8 | 3,639 |