Ōsa, Okayama
Ōsa was a town located in Atetsu District, Okayama Prefecture, Japan.
As of 2003, the town had an estimated population of 3,922 and a density of 32.35 persons per km². The total area was 121.25 km².
On March 31, 2005, Ōsa, along with the towns of Shingō, Tessei and Tetta, was merged into the expanded city of Niimi.
