| Mattoon Formation | |
| Type: | Formation |
| Age: | Pennsylvanian |
| Period: | Pennsylvanian |
| Region: | Illinois and Indiana |
| Country: | United States |
| Unitof: | McLeansboro Group |
| Overlies: | Bond Formation |
The Mattoon Formation is a geologic formation in Illinois. It preserves fossils dating back to the Carboniferous period.