| St. Maughan's Formation | |
| Type: | Formation |
| Age: | Devonian |
| Period: | Devonian |
| Prilithology: | Mudstone |
| Otherlithology: | Sandstone, Conglomerate |
| Region: | Wales |
| Unitof: | Old Red Sandstone |
The St. Maughan's Formation is a geologic formation in Wales. It preserves fossils dating back to the Devonian period.