Ōhara (大原郡, Ōhara-gun) was a district located in Shimane Prefecture, Japan.
In 2003, the district had an estimated population of 30,838 and a density of 124.74 persons per km2. The total area was 247.21 km2.
雲南市(うんなんし)は大東町・加茂町・木次町・三刀屋町・吉田村・掛合町の6町村が合併して平成16年11月1日に誕生しました。