Carthage
- County:
- Hancock County
- County Seat:
- Yes
- Area (mi²):
- 2.529
- State:
- Illinois
Carthage is a city located in Hancock County, Illinois. Carthage has a 2026 population of 2,431. It is also the county seat of Hancock County. Carthage is currently declining at a rate of -1.06% annually and its population has decreased by -2.99% since the most recent census, which recorded a population of 2,506 in 2020.