Ōnuma District

Ōnuma (大沼郡) is a district of Fukushima Prefecture, Japan.

As of 2008, the district has an estimated population of 29,787 and a density of 34.2 persons per km2. Its total area is 870.51 km2.

It contains one village (Shōwa) and three towns: Aizumisato, Kaneyama, and Mishima.