was a town located in Iishi District, Shimane Prefecture, Japan.
As of 2003, the town had an estimated population of 8,442 and a density of 102.10 persons per km<sup>2</sup>. The total area was 82.68 km<sup>2</sup>.
On November 1, 2004, Mitoya, along with the towns of Daità Â, Kamo and Kisuki (all from à Âhara District), the town of Kakeya, and the village of Yoshida (all from Iishi District), was merged to create the city of Unnan.