Sao Hai (Thai: เสาไห้, pronounced [sǎw hâj]) is a district (amphoe) in Saraburi province, central Thailand.

The first record of a central district office is in Sao Hai at Tambon Sala Li Lao.

At the same time, the Sao Hai district office was moved to Tambon Suan Dokmai.

Three years later it was moved again to Tambon Sao Hai near Chao Poo Shrine.

The pillar became very sad, floated back to Saraburi on the Chao Phraya and Pa Sak Rivers, and sunk there.