The area around Nakhon Si Thammarat was part (according to some scholars even the centre) of the Srivijaya kingdom from the 3rd century. At the height of the Khmer Empire, the region was occupied by the Khmers up until the 17th century. The name of the region was formally called Nokor Sri Thammareach.
The Ramkhamhaeng stele lists it among the areas within the realm of Sukhothai. After the fall of Sukhothai it fell it its successor, the Ayutthaya kingdom and was one of the tributary kingdoms or 1st class provinces.
With the thesaphiban administrative reforms the kingdom was more closely integrated into the Thai state and formed the Monthon Nakhon Si Thammarat. With the abolishment of the monthon system in 1932, the province covering only the central parts of the former kingdom became the top-level administrative subdivision of Thailand
