Daisen is located in the flatlands of central Akita Prefecture. The area of the city is greater than the total metropolitan area of Tokyo. Daisen is bounded by the Ōu Mountains in the east, the Dewa Mountains in the center of the prefecture in the west, the former town of Kakumagawa between the Omono River and the Yokote River in the south, and the area slightly south of the summit of Mount Oishi in the north. The mountains of the Dewa Mountain Range in the western part of the city and the Ōu Mountains in the eastern part of the city surround the Senboku Plain in the northern part of the Yokote Basin.The Omono River, a first-class river, flows from the south to the northwest of the city. The highest peak in Daisen is Mount Kosugi (1,229 meters) in eastern Daisen.
