Ranong (Thai: ระนอง (Pronunciation)) is a town (thesaban mueang) in southern Thailand, capital of the Ranong Province and the Mueang Ranong district. The town covers completely the area of the tambon Khao Niwet (เขานิเวศน์). As of 2005 it has a population of 16,163.

Ranong is located at the estuary of the Pak Chan (or Kraburi) River, opposite Myanmar's Victoria Point. The Tenasserim Hills rise directly to the east of Ranong, and another small ridge runs along the edge of the estuary to the town's north.

Ranong has a tropical monsoon climate (Köppen climate classification Am). There is little variation in the temperature throughout the year, although the pre-monsoon months (February to April) are somewhat hotter in the day. However, Ranong's position to the west of the Tenasserim Hills means that the monsoon season's rains are greatly amplified, resulting in torrential rains from May until October, and significant rainfall in the transition months of April and November.