| SIAC | Safety Issue Assessment Center 
| Others |
| SIAC | San Isidro Automovil Club
| Others |
| SIAC | School Improvement Accountability Committee
| Others |
| SIAC | Securities Industry Automation Corporation
| Others |
| SIAC | Security Industry Alarm Coalition
| Others |
| SIAC | Shanghai International Auto City
| Others |
| SIAC | Singapore International Arbitration Centre
| Others |
| SIAC | Societa Italiana Auto Cars
| Others |
| SIAC | Southern Indiana Athletic Conference
| Others |
| SIAC | Southern Intercollegiate Athletic Conference
| Others |
| SIAC | Southern Irish Asphalt Company
| Others |
| SIAC | Spatial Information and Analysis Consortium
| Others |
| SIAC | Special Immigration Appeals commission
| Others |
| SIAC | State Institute for Administrative Career
| Others |
| SIAC | Syndicat des Industries Automobiles du Cameroun
| Others |