The province is on the Malay Peninsula, on the shore of the Andaman Sea. It is separated from Songkhla Province by the Nakhon Si Thammarat mountain range, and from Malaysia by the Sankalakhiri mountains.
Until 1916 Satun was a small Malay state known as Kingdom of Setul Mambang Segara, closely related to Kedah Sultanate. After that date it was administered by a governor sent from Nakhon Si Thammarat. In 1897 Satun became part of Monthon Syburi (now Kedah), which in 1909 was divided between British Empire and Siam as part of Anglo-Siamese Treaty of 1909. While most of Kedah was ceded to Britain, Satun was awarded to Siam because it had a relatively large Thai population. Satun was then incorporated into Monthon Phuket. The monthon system was ended in 1933, and Satun Province became a first-level subdivision of Thailand.
Satun is one of the four provinces of Thailand which have a Muslim majority: 67.8 percent are Muslim and 31.9 percent are Buddhists. Most of the Muslims have some ethnic-Malay ancestry, though only 9.9 percent of the population claims to be ethnically Malay. The Malay dialect used in Satun is distinctly different from Patani Malay and is much closer to the Kedah dialect of Malay, with a significant admixture of Thai influences.