Nanto is a city in Toyama Prefecture, Japan. It is in a mountainous area in the south-west corner of the prefecture just north of Gifu Prefecture. It is home to the Gokayama UNESCO World Heritage site. As of 28 February 2018, the city had an estimated population of 51,669 in 17,761 households and a population density of 75.8 persons per km². Its total area is 668.64 square kilometres.