Sakon Nakhon (sometimes written Sakhon Nakhon) is a city (thesaban nakhon) in Thailand within the Isan region, and capital city of Sakon Nakhon Province as well as Mueang Sakon Nakhon District, with a population of approximately 76,000. Sakon Nakhon covers the whole tambon of That Choeng Chum and parts of tambons Ngio Don, Huai Yang, Dong Mafai, That Na Weng and Hang Hong. Sakon Nakhon is 651 km north-east of Bangkok by road.

During World War II, Sakon Nakhon became a haven for Free Thais, and a base for Communist activities in the late 1950s.

Sakon Nakhon lies on a flat plain at about 175 metres (574 ft) elevation on the south-west bank of Lake Nong Han, the largest lake of north-east Thailand. The town is surrounded by extensive farmland.

Sakon Nakhon has a tropical savanna climate (Köppen climate classification Aw). Winters are dry and very warm. Temperatures rise until April, which is hot with the average daily maximum at 35.1 °C (95.2 °F). The monsoon season runs from May through October, with heavy rain and somewhat cooler temperatures during the day, although nights remain warm.