San Thia is Khmer, meaning 'a place to gather salt'.

In 1900, Khwaeng San Thia was changed to a district and renamed Non Lao.

[1] Finally in the phase of Thai nationalism under Field Marshal Plaek Phibunsongkhram, the district name was changed to Non Thai in 1939 to remove the reference to the Lao population in the name.

Non Thai is divided into 10 sub-districts (tambons), which are further subdivided into 133 administrative villages (mubans).

Missing numbers are tambon which now form Phra Thong Kham District.