Humboldt is a city in Gibson and Madison counties, Tennessee. The population was 8,452 at the 2010 census, a decline of 1,015 from 2000. It is the principal city of and is included in the Humboldt, Tennessee Micropolitan Statistical Area, which is included in the Jackson, Tennessee-Humboldt, Tennessee Combined Statistical Area. It is Gibson County's largest city and Madison County's second largest city after Jackson.