The province songkhla is located on the Malay Peninsula, on the coast of the Gulf of Thailand.
In the north of the province is Songkhla lake, the largest natural lake in Thailand. This shallow lake covers an area of 1,040 km², and has a south-north extent of 78 kilometers. At its mouth on the Gulf of Thailand, near the city of Songkhla, the water becomes brackish. A small population of Irrawaddy Dolphins live in the lake, but are in danger of extinction due to accidental capture by the nets of the local fishing industry.