Grundy 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 37,535 people, with a population density of about 89.37 persons per square mile.
The county spans a total land area of 420.00 square miles (1,088.00 square kilometers). The administrative center and county seat is Morris, which often serves as a hub for local governance and services. The largest city within the county by population is Morris.
Geographically, Grundy County experiences varied elevations, with its highest point at Verona 640 ft and its lowest point at Morris 519 ft. The region operates in the UTC-6.