Koshigaya is a city located in the Saitama Prefecture of Japan. As of January 1, 2021, the city had an estimated population of 345,353 residents living in 158,022 households. It covers a total area of 60.24 square kilometres (23.26 sq mi), resulting in a population density of approximately 5,700 persons per km2.
The city is notably recognized for its production of daruma dolls. This traditional Japanese figurine serves as a significant cultural and artisanal characteristic of the region.