Kōriyama is a city in Fukushima Prefecture, Japan. As of 1 August 2023, the city had an estimated population of 321,938 people in 141760 households, and a population density of 425 persons per km2. The total area of the city is 757.20 square kilometers. Kōriyama is designated as a core city and functions as a commercial center for Fukushima Prefecture. Kōriyama is the third largest conurbation in the Tōhoku region.