[2] Per Japanese census data,[3] the population of Kinokawa has remained relatively steady over the past 60 years.

After the Meiji restoration, the area became was organized into 36 villages within Naga District, Wakayama with the creation of the modern municipalities system on April 1, 1889.

Kokawa was raised to town status on November 10, 1894, and Kishigawa on March 31, 1955 and Naga on July 1, 1955.

Kinokawa has a mayor-council form of government with a directly elected mayor and a unicameral city council of 22 members.

In terms of national politics, the city is part of Wakayama 2nd district of the lower house of the Diet of Japan.