IISG
| Acronym | Definition |
|---|---|
| IISG | Internationaal Instituut voor Sociale Geschiedenis (Dutch: International Institute of Social History; Amsterdam, Netherlands) |
| IISG | Illinois-Indiana Sea Grant (Urbana, Il) |
| IISG | Intelligent Information Systems Group (AGH University; Poland) |
| IISG | Interim Independent Scientists Group (International Union for Conservation of Nature) |