Mitsu, Okayama

 was a town located in Mitsu District, Okayama Prefecture, Japan.
As of 2003, the town had an estimated population of 10,124 and a density of 88.48 persons per km². The total area was 114.42 km².
On March 22, 2005, Mitsu, along with the town of Nadasaki (from Kojima District), was merged into the expanded city of Okayama.