Ōshima, Nagasaki (Nishisonogi)

Ōshima (大島町) was a town located in Nishisonogi District, Nagasaki Prefecture, Japan.

As of 2003, the town had an estimated population of 6,046 and a density of 453.56 persons per km2. The total area was 13.33 km2.

On April 1, 2005, Ōshima, along with the towns of Saikai (former), Ōseto, Sakito and Seihi (all from Nishisonogi District), was merged to create the city of Saikai.