Sungai Kolok is a subdistrict and border town located in the Sungai Kolok District of Narathiwat Province, Thailand. Situated on the international border with Malaysia, it serves as the capital of its namesake district and lies directly across from Rantau Panjang in the state of Kelantan.
The town is recognized as one of the largest and most prosperous districts within Narathiwat Province. It functions as a major economic center for the southern region of Thailand. As of 2005, the population of Sungai Kolok was recorded at 38,612.