| Abbreviation | Definition |
|---|---|
| OCCA | Ontario Control Contractors Association |
| OCCM | Office of Court Construction and Management |
| OCEW | On Center Each Way |
| OCI | Orascom Construction Industries |
| OCMC | Office of Construction Mitigation and Coordination |
| OCMC | Office of Construction Mitigation Coordination |
| OCO | Other Contractors, Opportunities for |
| OCPD | Overcurrent Protective Devices |
| OCS | Olori Construction Services |
| OCS | Ontario Construction Secretariat |
| OCSA | Ohio Construction Suppliers Association |
| OCUC | Ontario Construction User Council |
| OCV | Offshore Construction Vessel |
| ODAC | Open Distributed Application Construction |
| ODAC | Open Distributed Applications Construction |
| ODACC | Ontario Dispute Adjudication for Construction Contracts |
| ODCA | Oceanside Development and Construction Association |
| ODCA | Orillia and District Construction Association |
| ODCC | Oil Design and Construction Company |
| ODDC | One Draft Design and Construction |