| SIO | s for Input Output 
| Others |
| SIO | Saptam in One
| Others |
| SIO | Scalable Input Output
| Others |
| SIO | Scalable Input/ Output Initiative
| Others |
| SIO | Science Institute Of
| Others |
| SIO | Scripps Institution of Oceanography
| Others |
| SIO | Sea Ice Outlook
| Others |
| SIO | Second Institute of Oceanography
| Others |
| SIO | Section of International Organisations
| Others |
| SIO | Secure Identity Object
| Others |
| SIO | Security Information Object
| Others |
| SIO | Security Intelligence Operations
| Others |
| SIO | Seller Initiated Offer
| Others |
| SIO | Semanticscience Integrated Ontology
| Others |
| SIO | Senior Intelligence Officer
| Others |
| SIO | Senior Investigating Officer
| Others |
| SIO | Serial I O
| Others |
| SIO | Serial Input/Output
| Others |
| SIO | Serious Inquiries Only
| Others |
| SIO | Server Indirection Object
| Others |
| SIO | Service Improvement Operations
| Others |
| SIO | Service Information Object
| Others |
| SIO | Shareable Interface Object
| Others |
| SIO | Shock Induced Oscillation
| Others |
| SIO | Silicon Oxide
| Others |
| SIO | Simultaneous Interface Operation
| Others |
| SIO | Single Image Output
| Others |
| SIO | Siouan Languages
| Others |
| SIO | Skidaway Institute of Oceanography
| Others |
| SIO | Skin Innovation Overnight
| Others |
| SIO | Smart Inbound Optimization
| Others |
| SIO | Smithton, Tasmania, Australia
| Others |
| SIO | Social Insurance Organization
| Others |
| SIO | Social Investment Organization
| Others |
| SIO | Societas Internationalis Odontologica
| Others |
| SIO | Society for Integrative Oncology
| Others |
| SIO | Society of Interventional Oncology
| Others |
| SIO | Special Information Operations
| Others |
| SIO | Speelgoed Industrie Overijssel
| Others |
| SIO | Spit It Out
| Others |
| SIO | Standard I O
| Others |
| SIO | Standard Installation Organization
| Others |
| SIO | Stanford Internet Observatory
| Others |
| SIO | Start Input Output
| Others |
| SIO | Storage Input Output
| Others |
| SIO | Strategise Implement Operate
| Others |
| SIO | Student Information Online
| Others |
| SIO | Students Islamic Organisation
| Others |
| SIO | Students Islamic Organisation of India
| Others |
| SIO | Students Islamic Organization
| Others |
| SIO | Students Islamic Organization of India
| Others |
| SIO | Studentsamskipnaden i Oslo
| Others |
| SIO | Subscribers In Operation
| Others |
| SIO | Summary Instalment Orders
| Others |
| SIO | Super Input Output
| Others |
| SIO | Surety Information Office
| Others |
| SIO | Swarm Intelligence Optimization
| Others |
| SIO | System Input Output
| Others |
| SIO | Systems Integration Office
| Others |