Humboldt is a city in Richardson County, Nebraska, United States. The population was 800 at the 2020 census. Humboldt was platted in 186…Humboldt is a city in Richardson County, Nebraska, United States. The population was 800 at the 2020 census. Humboldt was platted in 1868. It was named after Humboldt, Tennessee, where an early settler had stayed while fighting in the Civil War.