The Phra I-suan contains a 1 m (3ft) Shiva linga which dates possibly to the 6th century CE.

Nakhon Si Thammarat was the administrative center of southern Thailand during most of its history. Originally a coastal city, silting moved the coastline away from the city.

It is one of the oldest towns in Thailand and most historians recognize the Tambralinga kingdom of Chinese records as a precursor of Nakhon Si Thammarat. With the fall of the Siamese capital of Ayutthaya in 1767 it regained independence, but returned to its allegiance on the founding of Bangkok. In the 17th century British, Portuguese and Dutch merchants set up factories here and carried on an extensive trade.