| Abbreviation | Definition |
|---|---|
| GMCA | Greater Manchester Combined Authority |
| GMS | General Medical Services |
| GMTA | Green Mountain Transit Authority |
| GNA | Good Neighbor Authority |
| GNBA | Guyana National Broadcasting Authority |
| GOA | Grant Of Authority |
| GPA | Georgia Ports Authority |
| GPHA | Grand Prairie Housing Authority |
| GPW | Gpw means: G = (Absolute Creator) GOD; p= (original energy &) power & w = (original representative) |
| GRA | Gambia Revenue Authority |
| GRA | Gambling Regulatory Authority |
| GRA | Ghana Revenue Authority |
| GRA | Gibraltar Regulatory Authority |
| GRA | Guyana Revenue Authority |
| GRA | Guyana Revenue Authority's |
| GRAA | Greater Rockford Airport Authority |
| GRCA | Grand River Conservation Authority |
| GSFA | Golden State Finance Authority |
| GTA | Greensboro Transit Authority |
| GTA | Guam Telephone Authority |