| Elwren Formation | |
| Type: | Formation |
| Age: | Mississippian |
| Period: | Mississippian |
| Region: | Indiana and Kentucky |
| Country: | United States |
| Unitof: | West Baden Group |
| Underlies: | Beech Creek Limestone |
| Overlies: | Reelsville Limestone |
The Elwren Formation is a geologic formation in Kentucky. It preserves fossils dating back to the Carboniferous period.