Chai Nat is one of the central provinces (changwat) of Thailand. Neighbouring provinces are Nakhon Sawan, Sing Buri, Suphan Buri, and Uthai Thani. The town of Chai Nat is 188 km north of Bangkok.

The provinces of Thailand are administrative divisions of the government of Thailand. The country is divided into 76 provinces proper, with one additional special administrative area. They are the primary local government units and act as juristic persons. They are divided into amphoe (districts) which are further divided into tambon, the next lower level of local government.