Belknap
- County:
- Johnson County
- County Seat:
- No
- Area (mi²):
- 1.057
- State:
- Illinois
Belknap is a village located in Johnson County, Illinois. Belknap has a 2026 population of 86. Belknap is currently declining at a rate of 0% annually and its population has decreased by 0% since the most recent census, which recorded a population of 86 in 2020.