was a town located in Kojima District, Okayama Prefecture, Japan.
As of 2003, the town had an estimated population of 15,872 and a density of 514.32 persons per km<sup>2</sup>. The total area was 30.86 km<sup>2</sup>.
On March 22, 2005, Nadasaki, along with the town of Mitsu (from Mitsu District), was merged into the expanded city of Okayama.