Lista de empresas
| Name | Province | City |
|---|---|---|
| OPP UHTHOFF Firing Range - Ontario Provincial Police | Ontario | Orillia |
| Opta Nanticoke Facility - Opta Inc. | Ontario | Nanticoke |
| Opta Regina Facility - Opta Inc. | Saskatchewan | Regina |
| Opta Waterdown Inc. - Opta Waterdown Inc. | Ontario | Waterdown |
| Orangeville - Holmes Agro | Ontario | Orangeville |
| Orangeville Compound - Geon Performance Solutions | Ontario | Orangeville |
| Orangeville Plasticizer - Geon Performance Solutions | Ontario | Orangeville |
| Orangeville Water Pollution Control Plant - Town of Orangeville | Ontario | Orangeville |
| Orca Sand and Gravel - Polaris Materials Corporation | Columbia Británica | Port McNeil |
| Oregon Tool Canada - Oregon Tool Canada Ltd. | Ontario | Guelph |
