Oku (邑久町 Oku-chō) was a town located in Oku District, Okayama, Japan.
On November 1, 2004 Oku was merged with the towns of Osafune and Ushimado, all from Oku District, to form the new city of Setouchi.
As of 2003, the town had an estimated population of 19,389 and a density of 282.19 persons per km². The total area was 68.71 km².