Iwata (磐田郡, Iwata-gun) was a district located in Shizuoka Prefecture, Japan.
As of 2003, the district had an estimated population of 109,260 and a density of 171.17 persons per km2. The total area before the dissolution was 638.31 km2.
On July 1, 2005, the towns of Misakubo and Sakuma, and the village of Tatsuyama, along with the cities of Tenryū and Hamakita, the town of Haruno (from Shūchi District), the towns of Hosoe, Inasa and Mikkabi (all from Inasa District), and the towns of Maisaka and Yūtō (both from Hamana District), were merged into the expanded city of Hamamatsu.[1] Iwata District was dissolved as a result of this merger.