thumb|Location of Aida District in Okayama Prefecture
is a district located in Okayama Prefecture, Japan.
As of 2003, the district has an estimated population of 31,845 and a density of 79.65 persons per km<sup>2</sup>. The total area is 399.83 km<sup>2</sup>.
Towns and villages
Aida District consists of the following village:
- Nishiawakura
History
Prior to March 31, 2005, Aida District included
- Aida
- Higashiawakura
- Mimasaka
- Nishiawakura
- Ōhara
- Sakutō
On that date, all but Nishiawakura merged to form the new city of Mimasaka.