
Buchanan County
- State:
- Missouri
- County Seat:
- Saint Joseph
Buchanan County's estimated 2025 population is 83,086 with a growth rate of 0.08% in the past year according to the most recent United States census data. Buchanan County is the 15th largest county in Missouri. The 2010 population was 89,071 and has seen a growth of -6.72% since that time.