Nankoku (南国市, Nankoku-shi) is a city located in Kōchi Prefecture, Japan. Strong in the fishing industry and the market industry, Nankoku-shi supplies most of Kochi's agricultural needs, because of the amount of fields and plantations. Kōchi Ryōma Airport, which serves the city of Kochi, is located southeast of Nankoku-shi. The city was formally named on October 1, 1959.
As of February 29, 2012, the city has an estimated population of 49,040, with 21,477 households and a population density of 391.22 persons per km². The total area is 125.35 km².