Ninohe (二戸郡, Ninohe-gun) is a rural district located in Iwate Prefecture, Japan.
As of June 1, 2019, the district has an estimated population of 11,797 with a density of 39.3 per km2 and an area of 300.03 km2.
The entire city of Ninohe, and parts of the city of Hachimantai and town of Kuzumaki were formerly part of Ninohe District.
The district consists of one town: The ancient county of Nukanobu (糠部郡, Nikanobu-gun) in Mutsu Province was divided into the counties of Ninohe, Sannohe, Kunohe and Kita in 1634.
Under the Tokugawa shogunate, Ninohe county consisted of 74 villages under the control of Morioka Domain.