Shimohei (下閉伊郡 Shimohei-gun) is a district located in Iwate Prefecture, Japan.
Following the merger of Tarō and Niisato into Miyako and as of 2003 population data, the district has an estimated population of 43,747 and a population density of 21.39 persons per km². The total area is 2,045.26 km².
There are two towns and two villages within the district.
- June 6, 2005: The town of Tarō and village of Niisato merged with the city of Miyako to create the city of Miyako.
- January 1, 2010: The village of Kawai merged with the city of Miyako to create the city of Miyako.
Coordinates: 39°52′N 141°47′E / 39.867°N 141.783°E