| Acronym | Definition |
|---|
| FIRB | Foreign Investment Review Board (Australia) |
| FIRB | Fondo per Gli Investimenti Della Ricerca di Base (Italian: Basic Research Investment Fund) |
| FIRB | Firing Boss (firefighting) |
| FIRB | Faculdades Integradas Rui Barbosa (Portuguese; Brazilian school) |
| FIRB | Faculdades Integradas Rio Branco (Portuguese: Integrated College Rio Branco; Rio Branco, Brazil) |
| FIRB | Far Infrared Background |
| FIRB | Flight Information Region Boundary |
| FIRB | Furrow Irrigated Raised Bed (crop planting technique) |
| FIRB | Forced Internal Recirculation Burner (Gas Technology Institute) |