GRTA
| Acronym | Definition |
|---|---|
| GRTA | Georgia Regional Transportation Authority |
| GRTA | Gruppo Ricerca Tecnologie Appropriate (Italian: Appropriate Technology Research Group; Cesena, Italy) |
| GRTA | Gas Rapid Thermal Anneal (heating method) |
| GRTA | General Refinery Turn Around (oil & gas industry) |
| GRTA | Greenwich Riding and Trails Association (Greenwich, CT) |
| GRTA | Grand Rapids Transit Authority |