List of fossiliferous stratigraphic units in Ontario
# List of fossiliferous stratigraphic units in Ontario

This is a list of stratigraphic units in Ontario bearing fossils.

| Group or formation | Period |
| - | - |
| Aberdeen Lake Formation | Ordovician |
| Amherstburg Formation | Devonian |
| Arkona Formation | Devonian |
| Arkona Shale | Devonian |
| Attawapiskat Formation | Silurian |
| Bad Cache Rapids Group/Surprise Creek Formation | Ordovician |
| Bertie Group/Williamsville Formation | Silurian |
| Black River Group/Bobcaygeon Formation | Ordovician |
| Black River Group/Ottawa Formation | Ordovician |
| Bobcaygeon Formation | Ordovician |
| Cabot Head Formation | Silurian |
| Cobourg Formation | Ordovician |
| DeCew Formation | Silurian |
| Detroit River Group/Lucas Formation | Devonian |
| Don Beds Formation | Canada |
| Dyer Bay Formation | Silurian |
| Ekwan River Formation | Silurian |
| Eramosa Formation | Silurian |
| Farr Formation | Ordovician |
| Fossil Hill Formation | Silurian |
| Gasport Formation | Silurian |
| Georgian Bay Formation | Ordovician |
| Goat Island Formation | Silurian |
| Guelph Formation | Silurian |
| Gull River Formation | Ordovician |
| Hamilton Group/Hungry Hollow Formation | Devonian |
| Irondequoit Limestone Formation | Silurian |
| Kettle Point black Shale | Devonian |
| Kwataboahegan Formation | Devonian |
| Lockport Formation | Silurian |
| Long Rapids Formation | Devonian |
| Lowville Formation | Ordovician |
| Manitoulin Formation | Silurian, Ordovician |
| Meaford Formation | Ordovician |
| Medina Group/Power Glen Formation | Silurian |
| Missinabi Formation | Canada |
| Murray Island Formation | Devonian |
| Nottawasaga Group/Georgian Bay Formation | Ordovician |
| Nottawasaga Group/Whitby Formation | Ordovician |
| Ohio Shale | Devonian |
| Onondaga Formation | Devonian |
| Ottawa Formation | Ordovician |
| Ottawa Group/Lowville Formation | Ordovician |
| Oxford Formation | Ordovician |
| Pamelia Formation | Ordovician |
| Power Glen Formation | Silurian |
| Power Glen Shale | Silurian |
| Queenston Formation | Ordovician |
| Rochester Shale | Silurian |
| Scarborough Formation | Canada |
| Sextant Formation | Devonian |
| Simcoe Group/Bobcaygeon Formation | Ordovician |
| Simcoe Group/Gull River Formation | Ordovician |
| Simcoe Group/Lindsay Formation | Ordovician |
| Simcoe Group/Verulam Formation | Ordovician |
| St. Edmund Formation | Silurian |
| Stooping River Formation | Devonian |
| Thorold Formation | Silurian |
| Trenton Group/Cobourg limestone Formation | Ordovician |
| Trenton Group/Sherman Fall limestone Formation | Ordovician |
| Verulam Formation | Ordovician |
| Williams Island Formation | Devonian |
