Ratchaburi province or Rat Buri is one of Thailand's seventy-six provinces (changwat) lies in Western Thailand. Neighbouring provinces are Kanchanaburi, Nakhon Pathom, Samut Sakhon, Samut Songkhram and Phetchaburi. In the west it borders the Tanintharyi Region of Myanmar.

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.