Osafune (長船町 Osafune-chō) was a town located in Oku District, Okayama, Japan.
On November 1, 2004 Osafune was merged with the towns of Oku and Ushimado, all from Oku District, to form the new city of Setouchi.
As of 2003, the town had an estimated population of 12,431 and a density of 424.27 persons per km². The total area was 29.30 km².