| Abbreviation | Definition |
|---|---|
| GPI | Graduate Photographer Institute |
| GPI | Graduate Preparation Institute |
| GPI | Great Plains Institute |
| GPID | Govind Palpitation Institute of Dance |
| GPMI | Global Payroll Management Institute |
| GPPI | Global Public Policy Institute |
| GRI | Gas Research Institute |
| GRI | Geosystems Research Institute |
| GRI | Getty Research Institute |
| GRI | Gothenburg Research Institute |
| GRI | Graduate Realtor Institute |
| GRI | Graduate REALTOR© Institute |
| GRI | Graduate REALTOR® Institute |
| GRI | Graduate REALTORS® Institute |
| GRIM | Gondol Research Institute for Mariculture |
| GRIP | Genealogical Research Institute of Pittsburgh |
| GRIPP | Gosling Research Institute for Plant Preservation |
| GSBI | Global Social Benefit Institute |
| GSEI | Global Social Enterprise Institute |
| GSI | Global Security Institute |