was a town located in Atetsu District, Okayama Prefecture, Japan.
As of 2003, the town had an estimated population of 3,961 and a density of 36.89 persons per km<sup>2</sup>. The total area was 107.37 km<sup>2</sup>.
On March 31, 2005, Tetta, along with the towns of à Âsa, Shingà  and Tessei (all from Atetsu District), was merged into the expanded city of Niimi.