Kuroiso (黒磯市, Kuroiso-shi), formerly a city in Tochigi Prefecture, Japan, is a district located in the modern city of Nasushiobara. The former city was founded on November 1, 1970.
In 2003, the city had an estimated population of 60,145 and a density of 175.29 persons per km2. The total area was 343.12 km2.