| SIEC | S International Equestrian Center 
| Others |
| SIEC | Secondary Introductory English centre
| Others |
| SIEC | Significant Impedance of Effective Competition
| Others |
| SIEC | Significant Impediment of Effective Competition
| Others |
| SIEC | Significant impediment to effective competition
| Others |
| SIEC | Sonya International Education and Careers
| Others |
| SIEC | Southern Illinois Electric Coop
| Others |
| SIEC | Southern Illinois Electric Cooperative
| Others |
| SIEC | Southern Indiana Education Center
| Others |
| SIEC | Southern Iowa Electric Cooperative
| Others |
| SIEC | Spirit of International Education Career
| Others |
| SIEC | State Independent Electoral Commission
| Others |
| SIEC | State Interoperability Executive Committee
| Others |
| SIEC | State Interoperability Executive Committees
| Others |
| SIEC | State Interoperability Executive Council
| Others |
| SIEC | Statewide Interoperability Exec Committee
| Others |
| SIEC | Statewide Interoperability Executive Comittee
| Others |
| SIEC | Statewide Interoperability Executive Committee
| Others |
| SIEC | Statewide Interoperability Executive Council
| Others |
| SIEC | Suicide Information And Education Center
| Others |
| SIEC | Suicide Information and Education Centre
| Others |
| SIEC | Summer Intensive English Course
| Others |
| SIEC | Sustainable Industries Education Centre
| Others |
| SIEC | Sydney International Equestrian Centre
| Others |
| SIEC | Symbiosis International Education Centre
| Others |