Sebastian County is a county located in the U.S. state of Arkansas. As of the most recent data available, the county has a population of approximately 115,071 people, with a population density of about 214.68 persons per square mile.
The county spans a total land area of 536.00 square miles (1,388.00 square kilometers). The administrative center and county seat is , which often serves as a hub for local governance and services. The largest city within the county by population is Fort Smith.
Geographically, Sebastian County experiences varied elevations, with its highest point at Hartford 650 ft and its lowest point at Greenwood 0 ft. The region operates in the UTC-6.