Kalasin is a city in northeast Thailand, the capital of Kalasin Province. As of 2015, it has a population of 34,429 It covers the whole tambon Kalasin of the Mueang Kalasin District, an area of 16.96 km2 (6.55 sq mi). Kalasin lies 513 kilometres (319 mi) north-northeast of Bangkok by road.