| OIEC | Obaidly ISCO Engineering Company 
| Others |
| OIEC | Office of Injured Employee Counsel
| Others |
| OIEC | Office of Institutional Equity and Compliance
| Others |
| OIEC | Office of Interoperable and Emergency Communications
| Others |
| OIEC | Ogimaawin Indigenous Education Council
| Others |
| OIEC | Oil Industries Engineering and Construction
| Others |
| OIEC | Oil Industries Engineering Construction
| Others |
| OIEC | Oklahoma Industrial Energy Consumers
| Others |
| OIEC | Oman International Exhibition Centre
| Others |
| OIEC | Oregon International Education Consortium
| Others |
| OIEC | Overseas International Education Centres
| Others |