| Abbreviation | Definition |
|---|---|
| GSIT | Girijabai Sail Institute Of Technology |
| GSLI | Girl Scout Leadership Institute |
| GSLI | Gloria Steinem Leadership Institute |
| GSLI | Graduate Student Leadership Institute |
| GSLI | Great Salt Lake Institute |
| GSOI | Grozny State Oil Institute |
| GSSI | Gatorade Sports Science Institute |
| GSWI | Granite State Woodland Institute |
| GTHBAUDI | Greater Toronto Home Builders Association-Urban Development Institute |
| GTI | Granite Technical Institute |
| GTI | Guelph Turfgrass Institute |
| GTIB | Gestalt Training Institute of Bermuda |
| GTIB | Guarantee Trust Institute of Business |
| GTIM | Global Tech Institute of Management |
| GTMI | Georgia Tech Manufacturing Institute |
| GTRI | Georgia Tech Research Institute |
| GTTI | Gambian Technical Training Institute |
| GTTI | Gedee Technical Training Institute |
| GTTI | George Telegraph Training Institute |
| GTTI | Global Tactical Training Institute |