| Acronym | Definition |
|---|
| SIA | Security Industry Association |
| SIA | Semiconductor Industry Association |
| SIA | Securities Industry Association (merged into Securities Industry & Financial Markets Association) |
| SIA | Security Industry Authority (UK) |
| SIA | Sistemi Informativi Aziendali (Italian: Business Information Systems, Ltd.) |
| SIA | Smithsonian Institution Archives (est. 1846) |
| SIA | Services to Improve Access (Ministry of Health; New Zealand) |
| SIA | Subaru of Indiana Automotive, Inc. (Lafayette, IN) |
| SIA | Stable Isotope Analysis (biology) |
| SIA | Senior Internal Auditor (accounting; various companies) |
| SIA | Sustainability Impact Assessment (trade) |
| SIA | Société des Ingénieurs de l'Automobile (French: Society of Automotive Engineers) |
| SIA | Seoul Institute of the Arts (Seoul, South Korea) |
| SIA | Salon International de l'Agriculture (French: International Exhibition of Agriculture) |
| SIA | Social Impact Assessment |
| SIA | Servicios de Información y Asesoría (Spanish: Information and Advisory Services; Guatemala) |
| SIA | Scaffold Industry Association |
| SIA | Social Insurance Agency (various locations) |
| SIA | Schweizerischer Ingenieur- und Architektenverein |
| SIA | Singapore Institute of Architects |
| SIA | Scsi Industry Association |
| SIA | Symantec Intruder Alert |
| SIA | Subaru Isuzu Automotive |
| SIA | Starting Instruction Address |
| SIA | Subaru of Indiana Automotive |
| SIA | Semiconductor Industries Association |
| SIA | Shenyang Institute of Automation (est. 1958; China) |
| SIA | Spinal Injury Association (various locations) |
| SIA | Safety Institute of Australia |
| SIA | System Impact Assessment |
| SIA | Satellite Industry Association |
| SIA | Société Suisse des Ingénieurs et des Architectes |
| SIA | Society for Industrial Archeology |
| SIA | Sam I Am (band) |
| SIA | Security Integration Architecture |
| SIA | SOCO International Plc (UK) |
| SIA | Survivors of Incest Anonymous |
| SIA | Societa Italiana di Andrologia (Italian) |
| SIA | Summit International Awards (marketing communications industry) |
| SIA | Service de l'Information Aéronautique (French: Aeronautical Information Service; General Directorate of Civil Aviation; France) |
| SIA | Professional Ski Instructors Association of Japan |
| SIA | Stuck in Active (Refers to DUAL-3-SIA error message of EIGRP) |
| SIA | Securities Institute of America |
| SIA | Solutions for Intelligence Analysis (various organizations) |
| SIA | Singapore International Airlines (ICAO code) |
| SIA | Servizio Informazioni Aeronautiche (Italian: Air Intelligence Service) |
| SIA | Subject Information Access |
| SIA | Sorry in Advance |
| SIA | Spokane International Airport |
| SIA | Società Interbancaria per l'automazione (Interbank Association for Automation) |
| SIA | Shareware Industry Awards |
| SIA | Sport Industry Awards (UK) |
| SIA | Sequential Injection Analysis |
| SIA | Saitama International Association (Japan) |
| SIA | Statistical Image Analysis (mathematics) |
| SIA | Staffing Industry Analysts, Inc. (Los Altos, California) |
| SIA | Supplementary Immunization Activities |
| SIA | Schools Insurance Authority (Sacramento, CA) |
| SIA | Students in Action |
| SIA | Swiss Insurance Association |
| SIA | Simplex Investment Advisors (Japan) |
| SIA | Società Italiana di Artroscopia |
| SIA | Special Interest Alien |
| SIA | Sorry I Asked (chat) |
| SIA | Sugar Industry Authority (Jamaica) |
| SIA | Ski Industries America |
| SIA | Società Italiana di Arboricoltura |
| SIA | Spaceweek International Association |
| SIA | Service in Information & Analysis Limited (London, UK) |
| SIA | Solvents Industry Association (London, UK) |
| SIA | Sabiedriba ar Ierobezotu Atbildibu (Latvian: Limited Liability Company) |
| SIA | Serial Interface Adaptor |
| SIA | Safety Institute of America (Lexington, SC) |
| SIA | Syrian Investment Agency |
| SIA | Singapore International Airport |
| SIA | Structural Inventory & Appraisal (engineering; various locations) |
| SIA | Session Initiation Application |
| SIA | Stable Implementation Agreements (Bellcore) |
| SIA | Sistema de Información Aduanero (Spanish: Customs Information System) |
| SIA | Socially Intelligent Agent |
| SIA | Sudden Ionospheric Absorption (astrophysics) |
| SIA | Standard Instrument Approach |
| SIA | Shareware Industry Association |
| SIA | Soldiers in Arms (gaming clan) |
| SIA | Starfleet Intelligence Agency (Star Trek) |
| SIA | System Interface Agreement |
| SIA | State Implementing Agency (India) |
| SIA | Salary Increase Authorization |
| SIA | Statistical Implicative Analysis |
| SIA | Storage Instantaneous Audimeter |
| SIA | Station Interface Adapter |
| SIA | Scalable Interconnect Architecture |
| SIA | Swap-In Arrears |
| SIA | Sciences et Initiatives pour l'Afrique (French: Science and Initiatives for Africa) |
| SIA | Sistema de Informação Aduaneiro (Portuguese: Customs Information System) |
| SIA | Scanner Interface Assembly |
| SIA | Swiss Industrial Abrasive |
| SIA | Screen Imagination Agency |
| SIA | Sentral Sykehuset I Akershus |
| SIA | Special Interface Adapter |
| SIA | System Interface Assembly |
| SIA | Student Initiated Assignment |
| SIA | Sociedad Argentina de Inmunologia |
| SIA | Shuttle Induced Atmosphere (US NASA) |
| SIA | Services Internetworking Architecture (Sedona) |
| SIA | Signal Indicated Alarm |
| SIA | Self Initiated Activity |
| SIA | Syra Intergalactic Arms (gaming) |
| SIA | Soroptimists International of the Americas |
| SIA | Structured Improvement Activity |
| SIA | Startegic Issues Analysis |
| SIA | Specialized Individual Assistance |
| SIA | Special Intelligence Australia |
| SIA | Supervision, Inspection and Administration (US Army) |
| SIA | Strategic Internet Alliance |
| SIA | Standardized IDRS/CFOL Access |
| SIA | Sudanese Institute of Architects |
| SIA | Strategic Integral Approach |