| Acronym | Definition |
|---|
| GSI | General Steel Holdings, Inc. (Beijing, China) |
| GSI | Gesellschaft für Schwerionenforschung (German Federal Research Institute f |
| GSI | Global Security Institute |
| GSI | Global System Integrator (various companies) |
| GSI | Global Security International (Daphne, AL) |
| GSI | Government Secure Intranet |
| GSI | Geological Survey of India |
| GSI | Grid Security Infrastructure (software) |
| GSI | Green Stormwater Infrastructure (various locations) |
| GSI | Goldman Sachs International |
| GSI | Global Surf Industries (Australia) |
| GSI | Global Subsidies Initiative (International Institute for Sustainable Development) |
| GSI | Geographical Survey Institute (Ibaraki, Japan) |
| GSI | Grid Security Infrastructure |
| GSI | General Server Interface |
| GSI | Great Software Ideas |
| GSI | Geological Society of Iowa |
| GSI | Gas Safety Inspection (UK) |
| GSI | Graphic Systems, Inc. (various locations) |
| GSI | Greater Spokane Incorporated (Chamber of Commerce and Economic Development Council; Spokane, WA) |
| GSI | Geological Survey of Ireland (est. 1845) |
| GSI | Graduate Student Instructor |
| GSI | Gonadosomatic Index |
| GSI | Group Self-Insurance |
| GSI | Genealogical Society of Ireland (est. 1990) |
| GSI | Global Severity Index |
| GSI | Genuine Software Initiative (Microsoft) |
| GSI | Global Science Institute (est. 2017) |
| GSI | Green Storage Initiative (Storage Networking Industry Association) |
| GSI | Gross Sexual Imposition |
| GSI | Gross Scheduled Income |
| GSI | Government Source Inspection |
| GSI | Global Sustainability Index (various locations) |
| GSI | Graduate Student Intern (various schools) |
| GSI | Gannett Satellite Information Network |
| GSI | Get Someone In |
| GSI | Guest Services, Inc. (Fairfax, VA) |
| GSI | Global Single Instance (Oracle) |
| GSI | Global Scale Impact (climate change) |
| GSI | Generic Safety Issue |
| GSI | Geological Strength Index |
| GSI | Get Sirius Info |
| GSI | Global Strategies International (various locations) |
| GSI | Giga-Scale Integration |
| GSI | Guest Satisfaction Index (hotel industry) |
| GSI | GomTV Star Invitational |
| GSI | GameSpy Industries |
| GSI | Gerontological Services, Inc. (Santa Monica, CA) |
| GSI | Glide Slope Indicator |
| GSI | Global Strike Integration (United States Strategic Command Joint Functional Component Command; US DoD) |
| GSI | Geological Survey Institute (Japan) |
| GSI | Global System Interrupt |
| GSI | Grid Security Interface |
| GSI | Government Systems Incorporated |
| GSI | Goal Systems International (Port Angeles, WA) |
| GSI | Geriatrics-For-Specialists Initiative |
| GSI | Genie Scientific, Inc. (manufacturer of lab fume hoods and metal cabinets) |
| GSI | Generic Software Interface |
| GSI | Geek Squad Installer (Best Buy) |
| GSI | Goddard Safety Initiative |
| GSI | Galil Seguridad Israelí (Spanish: Galil Israeli Security) |
| GSI | Guest Service Interaction |
| GSI | Geo Services International Ltd (UK) |
| GSI | Gulf States Initiatives |
| GSI | Graham Studios Inc (Philadelphia, Pennsylvania) |
| GSI | Ground Safety Instruction |
| GSI | GPETE Support Item |
| GSI | GoodSeed International |
| GSI | Globecomm Systems International (contractor) |
| GSI | Generator Services International, Inc. |
| GSI | Gerencia de Seguridad Institucional (Guatemala) |