Southern Thailand is located on the Malay Peninsula, the region covers an area of around 70,713 square kilometers, bounded to the north by Kra Isthmus as the narrowest part of the peninsula. The western part has steeper coasts, on the east side, river plains dominate the region.

The Southern Region of Thailand is covered by 14 provinces. It is also the gateway to hunderds of offshore tropical islands. Phuket is one of Thailand's top tourist destinations, and the country's largest island. Hat Yai in the Songkhla province, is the economic and commercial center for the lower south.

The largest river of Southern Thailand is the Tapi, which together with the Phum Duang River drains more than 8,000 square kilometers, which is more than 10 percent of the total area of Southern Thailand.

The Songkhla lake is the largest natural lake of Thailand, covering an area of 1,040 square kilometers, it borders the provinces of Songkhla and Phattalung. The largest artificial lake is the Chiao Lan Ratchaprapha dam, 165 square kilometers, within the Khao Sok national park, Surat Thani province.

Running through the middle of the peninsula are several mountain chains. The highest elevation is 1835 meters above sea level, in Khao Luang, Nakhon Si Thammarat Province. Ranging from the Kra Isthmus to Phuket island is the Phuket Mountain chain, which connects to the Tanao Si Mountain Range further north.

Almost parallel to the Phuket Mountain chain, a 100 kilometers to the east is the Nakhon Si Thammarat or Banthat chain, which begins with the Samui island and ends at the Malaysian border at the Koh Tarutao archipelago. The border to Malaysia is formed by the Sankalakhiri range, sometimes subdivided into the Pattani, Taluban and Songkhla chain. At the border with Malaysia, begins the Titiwangsa Mountain chain.

The limestone of the western coast of southern Thailand is eroded into many steep singular hills. Those parts submerged by the rising sea after the last ice age now form the many islands, like the well known Phi Phi Islands. Also quite famous is the so called James Bond Island in the Phang Nga Bay area, which was featured in the movie. The Man with the Golden Gun.

The Malay peninsula was settled since prehistoric times. Archeological remains were found in several caves, some used for dwellings, others as burial sites. The oldest remains were found in Lang Rongrien cave dating 38,000 to 27,000 years, and in the contemporary Moh Khiew cave, Krabi Province.