| Acronym | Definition |
|---|
| SII | Servicio de Impuestos Internos (Chile) |
| SII | Seiko Instruments, Inc. |
| SII | Securities and Investment Institute (UK) |
| SII | Standards Institution of Israel |
| SII | Strong Interest Inventory |
| SII | Síndrome de Intestino Irritable (Spanish: Irritable Bowel Syndrome) |
| SII | Systemic Infrastructure Initiative (Australia) |
| SII | Sensory Integration International |
| SII | Service Improvement Initiative (Canada) |
| SII | Standards Institute of Israel |
| SII | Social Insurance Institution of Finland |
| SII | Scalable Information Infrastructure |
| SII | Strategic Infrastructure Initiative |
| SII | Siilinjärvi (Finland) |
| SII | Scout II (truck model) |
| SII | Special Interest Item |
| SII | Successor In Interest |
| SII | Space Industries, Inc. |
| SII | Special Investigative Inquiry |
| SII | Statement of Intelligence Interest |
| SII | Sinclair Intimacy Institute |
| SII | Special Instructions Indicator |
| SII | System Internal Interface |
| SII | Software International Incorporated |
| SII | Security Investigation Index |
| SII | Systems Interface Inc. |
| SII | Service Identity Index |
| SII | Suitability Investigative Index |
| SII | Southern Industrial Institute, Inc. |
| SII | Soldier Information Interface |
| SII | Static/Stub Invocation Interface (CORBA client-side API) |
| SII | Sponsor Identification Index |
| SII | Strategic Inventory Initiative |
| SII | Semantic Information Integration (Digital Enterprise Research Institute; Ireland) |
| SII | Scott's Inspections Inc (San Antonio, TX) |