Fontana is a city in south central Miami County, Kansas, United States, and is part of the Kansas City metropolitan area. As of the 2020 cens…Fontana is a city in south central Miami County, Kansas, United States, and is part of the Kansas City metropolitan area. As of the 2020 census, the population of the city was 210. The name Fontana comes from the French word fontaine, meaning fountain or a spring-like water source. It was given to the small city from a spring near the town site.