| Acronym | Definition |
|---|
| GSIS | Government Service Insurance System (Philippines) |
| GSIS | Gyeonggi Suwon International School (Suwon, South Korea) |
| GSIS | Graduate School of International Studies |
| GSIS | German Swiss International School (The Peak, Hong Kong) |
| GSIS | Global State of Information Security (survey) |
| GSIS | Graduate School of Information Sciences |
| GSIS | Global Security and Intelligence Studies (Bachelor of Science Degree offered by ERAU) |
| GSIS | Grey Systems and Intelligent Services (IEEE International Conference) |
| GSIS | Graphics Standard Interface Standard |
| GSIS | Global System of Integrated Studies (Pakistan) |