| Stonington Formation | |
| Type: | Formation |
| Age: | Late Ordovician |
| Period: | Late Ordovician |
| Unitof: | Richmond Group (geology) |
| Subunits: | Ogontz Member and Bay de Noc Member |
| Underlies: | Big Hill Formation |
| Overlies: | Bill's Creek Shale |
The Stonington Formation is a geologic formation in Michigan. It preserves fossils dating back to the Ordovician period.