Phatthalung was formerly known as Mardelong (Jawi: مردلوڠ) in Malay, especially during the time when the region came under Muslim influence.[1]

During the reign of King Ramathibodi I of the Ayutthaya kingdom in the 14th century Phatthalung became one of twelve royal cities. At the end of the 18th century King Rama I submitted the city to the Ministry of Defense, which was responsible for all the southern provinces. During the administrative reform by King Chulalongkorn Phatthalung became part of the Monthon Nakhon Si Thammarat.