| Big River State Forest | |
| Iucn Category: | VI |
| Map: | Illinois |
| Map Width: | 225 |
| Location: | Henderson County, Illinois, USA |
| Nearest City: | Keithsburg, Illinois |
| Coordinates: | 41.0103°N -90.9125°W |
| Area: | 2900acres |
| Established: | 1925 |
| Governing Body: | Illinois Department of Natural Resources |
Big River State Forest is a conservation area on 2900acres in Henderson County, Illinois, United States. The land was first acquired in 1925 as only a 200acres refuge, but subsequent land purchases raised the total to 2900acres.