Washington
- County:
- Tazewell County
- County Seat:
- No
- Area (mi²):
- 8.55
- State:
- Illinois
Washington is a city located in Tazewell County, Illinois. Washington has a 2026 population of 15,857. Washington is currently growing at a rate of 0.03% annually but its population has decreased by -1.29% since the most recent census, which recorded a population of 16,064 in 2020.