| SIRR | Scheduled Inventory Reagent Replacement 
| Others |
| SIRR | Serving the Incarcerated and Recently Released
| Others |
| SIRR | Social Internal Rate of Return
| Others |
| SIRR | Societal Impact and Relevance of Research
| Others |
| SIRR | Society for Immigrant and Refugee Rights
| Others |
| SIRR | Software Improvement Recommendation Report
| Others |
| SIRR | Software Integration Readiness Review
| Others |
| SIRR | Southern Industrial Railroad
| Others |
| SIRR | Special Initiative for Rebuilding and Resiliency
| Others |