Oguni is a town located in Yamagata Prefecture, Japan. As of 29 February 2020, the town had an estimated population of 7,376 in 3020 households, and a population density of 10 persons per km2. The total area of the town is 737.56 square kilometres (285 sq mi).

Yamagata Prefecture is a prefecture of Japan located in the Tōhoku region of Honshu. Yamagata Prefecture has a population of 1,028,055 and has a geographic area of 9,325 km2. Yamagata Prefecture borders Akita Prefecture to the north, Miyagi Prefecture to the east, Fukushima Prefecture to the south, and Niigata Prefecture to the southwest.