Madison County is a county located in the U.S. state of Illinois. As of the most recent data available, the county has a population of approximately 258,941 people, with a population density of about 357.16 persons per square mile.
The county spans a total land area of 725.00 square miles (1,878.00 square kilometers). The administrative center and county seat is Edwardsville, which often serves as a hub for local governance and services. The largest city within the county by population is Granite City.
Geographically, Madison County experiences varied elevations, with its highest point at New Douglas 619 ft and its lowest point at Hartford 0 ft. The region operates in the UTC-6.