| Abbreviation | Definition |
|---|---|
| SIDC | State Industrial Development Corporation |
| SIDCO | Small Industries Development Corporation |
| SIE | Scottish Institute for Enterprise |
| SIE | Stu Import Export, Inc. |
| SIEG | Shanxi International Electricity Group |
| SIG | Schweizer Industrie Gesellschaft |
| SIG | Schweizerische Industrie Gesellschaft |
| SIG | Susquehanna International Group, L.L.P. |
| SIGH | Surgical Instrument Group Holdings Ltd |
| SIH | SAS International Hotels |
| SIH | Soros International House |
| SII | Investments Inc |
| SII | Seiko Instruments Inc |
| SII | Seiko Instruments, Inc. |
| SII | Steico Industries, Inc. |
| SII | System Integrators, Inc. |
| SIITAM | Sun International Institute for Technology and Management |
| SIJ | Shuswap Internet Junction |
| SIJT | Super Inkjet Technology |
| SIL | Sheep Improvement Ltd |