| Acronym | Definition |
|---|
| ESI | Electronic Supplementary Information |
| ESI | Electrospray Ionization |
| ESI | Electronically Stored Information |
| ESI | European Software Institute (Bizkaia-Spain) |
| ESI | Edge Side Includes (markup language) |
| ESI | Enterprise Software Initiative (US DoD) |
| ESI | Environmental Sustainability Index |
| ESI | Express Scripts, Inc. |
| ESI | Environmental Sensitivity Index |
| ESI | End System Identifier (ISO) |
| ESI | Environmental Services, Inc. (Jacksonville, FL) |
| ESI | Excess Share Insurance |
| ESI | Epidural Steroid Injection (medical) |
| ESI | Embedded Systems Institute (Netherlands) |
| ESI | Economic Strategy Institute |
| ESI | Epidural Steroid Injections |
| ESI | Electronic Signatures and Infrastructures |
| ESI | Extended Source Index |
| ESI | Early Supplier Involvement |
| ESI | Electron Spectroscopic Imaging |
| ESI | Election Science Institute (San Francisco, United States) |
| ESI | Environmental Solutions International |
| ESI | Employee Satisfaction Index |
| ESI | Echellette Spectrograph and Imager (Keck Observatory) |
| ESI | Employment Status Indicator (UK) |
| ESI | Enhanced Serial Interface |
| ESI | Extremely Sensitive Information |
| ESI | Escadron Special d'Intervention (French: Special Squadron of Intervention; Belgian counter-terrorist group) |
| ESI | Engineers and Surveyors Institute (Chantilly, VA) |
| ESI | Ecological Site Inventory (EPA) |
| ESI | Export Slaughter Interval (Australia) |
| ESI | Expanded Site Investigation |
| ESI | Educational Services Institute |
| ESI | EAD System Interface |
| ESI | Electrical Safety Inspector |
| ESI | Energy Savings Insurance |
| ESI | Environmentally Sensitive Index |
| ESI | EnviroSolutions, Inc. (Virginia waste management company) |
| ESI | External System Interface(s) |
| ESI | Explosives Safety Inspection |
| ESI | Equine Studies Institute |
| ESI | External Synchronization Interface |
| ESI | Emergency Services Interface |
| ESI | Externally Specified Index |
| ESI | Espresso Services Inc. (Minneapolis, Minnesota) |
| ESI | Extremidad Superior Izquierda (Spanish: Left Arm) |
| ESI | Enterprise Services Infrastructure |
| ESI | Effective Solutions Inc. |
| ESI | Escuela Superior Internacional (Guatemala school) |
| ESI | Electronic Security Industry |
| ESI | Ethernet Service Interworking (Ciena) |
| ESI | Extra Sensitive Information |
| ESI | Environmental Science, Inc. |
| ESI | Executive Systems, Incorporated |
| ESI | Externally Specified Indexing |
| ESI | Electronic Salesmasters Incorporated (Beachwood, OH) |
| ESI | Especially Sensitive Information |
| ESI | Edge Sports Inc. |
| ESI | Essential Sustainment Item |
| ESI | European Simulation Internet |
| ESI | Employee Skills Inventory/Index) |
| ESI | Energy Solution Insulation, Inc. (Saginaw, Michigan) |
| ESI | Engineers Supplemental Instructions |
| ESI | Electrostatic Spark Ignition |
| ESI | Eletrodos Seletivos a Ions (Ion Selective Electrodes) |