Hua Sai (Thai: หัวไทร, pronounced [hǔa̯ sāj]) is a district (amphoe) in the southeastern part of Nakhon Si Thammarat province, southern Thailand.

When the center was moved in 1906 to tambon Hua Sai, the district was renamed accordingly.

In the same year the district office was moved to its present location in village eight of tambon Hua Sai.

[1] The district is divided into 11 sub-districts (tambons), which are further subdivided into 99 villages (mubans).

This Nakhon Si Thammarat Province location article is a stub.