| 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 |