Kōriyama (郡山市, Kōriyama-shi) is a city in Fukushima Prefecture, Japan. As of 1 January 2020, the city has an estimated population of 322,996 people in 141760 households, and a population density of 430 persons per km2. The total area of the city is 757.20 square kilometres. Kōriyama is designated as a core city and functions as a commercial centre for Fukushima Prefecture. Kōriyama is the third-largest conurbation in the Tōhoku region.