Kalasin is one of Thailand's seventy-six provinces, located in upper northeastern Thailand, also called Isan. The province was established by the Act Establishing Changwat Kalasin, BE 2490, and it came into existence on 1 October 1947. Neighboring provinces are Sakon Nakhon, Mukdahan, Roi Et, Maha Sarakham, Khon Kaen, and Udon Thani.