| Lucas Formation | |
| Type: | Formation |
| Age: | Middle Devonian |
| Period: | Middle Devonian |
| Region: | Michigan and Ohio |
| Country: | United States |
| Unitof: | Detroit River Group |
| Underlies: | Anderdon Limestone and Dundee Formation |
| Overlies: | Amherstburg Formation |
The Lucas Formation is a geologic formation in Michigan. It preserves fossils dating back to the Devonian period.