Chatham
- County:
- Sangamon County
- County Seat:
- No
- Area (mi²):
- 7.406
- State:
- Illinois
Chatham is a village located in Sangamon County, Illinois. Chatham has a 2026 population of 14,639. Chatham is currently growing at a rate of 0.43% annually and its population has increased by 1.55% since the most recent census, which recorded a population of 14,415 in 2020.