Nagi (奈義町, Nagi-chō) is a town located in Katsuta District, Okayama Prefecture, Japan.

After the Meiji restoration, the villages of Kitayoshino, Toyota and Toyonami were established with the creation of the modern municipalities system on June 1, 1889.

Nagi has a mayor-council form of government with a directly elected mayor and a unicameral town council of ten members.

Nagi, collectively with the city of Tsuyama and the towns of Kagami and Shōō, contributes four members to the Okayama Prefectural Assembly.

In terms of national politics, the town is part of the Okayama 3rd district of the lower house of the Diet of Japan.

The JR West Kishin Line runs on the south side of the town, and the Inbi Line runs on the west and north sides of the town; however, Nagi does not have any passenger railway service.