Isa (伊佐市, Isa-shi) is a city located in Kagoshima Prefecture, Japan.

The Kawauchi River runs through the city, which is surrounded by the Kyushu Mountains, and the urban center is part of the Oguchi Basin, with an elevation of about 180 meters.

On April 1, 1889, the villages of Oguchi, Yamano, and Hazuki were established with the creation of the modern municipalities system.

Likewise, the villages of Hishikari and Tara were established on April 1, 1889 with the creation of the modern municipalities system.

[5] Isa has a mayor-council form of government with a directly elected mayor and a unicameral city council of 16 members.

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