| Acronym | Definition |
|---|
| ISSI | Integrated Silicon Solution, Inc. (San Jose, CA) |
| ISSI | Institute of Strategic Studies, Islamabad (Pakistan) |
| ISSI | Inter Switching System Interface |
| ISSI | International Space Science Institute |
| ISSI | International Society for Scientometrics and Informetrics (Belgium; est. 1993) |
| ISSI | Islamic State of Syria & Iraq |
| ISSI | Inter-Switching System Interface |
| ISSI | International Society for Self and Identity |
| ISSI | International Society for Skin Imaging (Bochum, Germany) |
| ISSI | International Summer Science Institute (Weizmann Institute, Israel) |
| ISSI | Internet Security Systems Inc. |
| ISSI | Individual Short Subscriber Identity (Terrestrial Trunked Radio) |
| ISSI | IBM Standard Software Installer |
| ISSI | Inter-RF Sub-System Interface |
| ISSI | Institute of Social Sciences Information |
| ISSI | Industrial Supply Solutions, Inc. (Salisbury, NC) |
| ISSI | Integrated Silicon Solution, Incorporated |
| ISSI | Insight Software Solutions, Inc. |
| ISSI | International Scattering Society, Inc. (ash scattering company) |