
Gallia County
- State:
- Ohio
- County Seat:
- Gallipolis
Gallia County's estimated 2025 population is 28,898 with a growth rate of -0.15% in the past year according to the most recent United States census data. Gallia County is the 73rd largest county in Ohio. The 2010 population was 31,066 and has seen a growth of -6.98% since that time.