Buchanan County is a county located in the U.S. state of Missouri. As of the most recent data available, the county has a population of approximately 85,998 people, with a population density of about 209.75 persons per square mile.
The county spans a total land area of 410.00 square miles (1,062.00 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 St. Joseph.
Geographically, Buchanan County experiences varied elevations, with its highest point at De Kalb 1,138 ft and its lowest point at Rushville 812 ft. The region operates in the UTC-6.