Phon Sai (Thai: โพนทราย, pronounced [pʰōːn sāːj]) is a district (amphoe) in the southeastern part of Roi Et province, northeastern Thailand.

The minor district (king amphoe) Phon Sai was established on 16 November 1976, when the two tambons, Phon Sai and Samkha, were split off from Suwannaphum district.

[2] The district is divided into five sub-districts (tambons), which are further subdivided into 58 villages (mubans).

Phon Sai is a township (thesaban tambon) which covers parts of tambon Phon Sai.

This Roi Et Province location article is a stub.