Aida, Okayama

 was a town located in Aida District, Okayama Prefecture, Japan.
As of 2003, the town had an estimated population of 3,625 and a density of 57.17 persons per km². The total area was 63.41 km².
On March 31, 2005, Aida, along with the towns of Mimasaka (former), Ōhara and Sakutō, the village of Higashiawakura (all from Aida District), and the town of Katsuta (from Katsuta District), was merged to create the city of Mimasaka.
In the 1990s, Aida's TI Circuit hosted two Formula One races called the Pacific Grand Prix.