Yamagata is the capital city of Yamagata Prefecture located in the Tōhoku region of northern Japan. As of 1 August 2023, the city had an estim…Yamagata is the capital city of Yamagata Prefecture located in the Tōhoku region of northern Japan. As of 1 August 2023, the city had an estimated population of 242,505 in 103,165 households, and a population density of 636 persons per km². The total area of the city is 381.58 square kilometres.