| Acronym | Definition |
|---|
| FISO | Fonds d'Investissement Social (French: Social Investment Fund) |
| FISO | Fundación Iberamericana de Seguridad y Salud Ocupacional (Spanish: Ibero-American Foundation of Occupational Safety and Health) |
| FISO | Fast In Slow Out |
| FISO | Formation en Implantologie du Sud-Ouest (French: Training in Implantology South West) |
| FISO | Flight Information Service Officer (UK) |
| FISO | Fantasy & Interactive Sports Online (forum) |
| FISO | Functionally Integrated Supporting Organization (tax) |
| FISO | Fault Isolation |
| FISO | Force Integration Staff Officer |
| FISO | Facility Information Security Officer (hospitals) |
| FISO | Fiscal Intermediary Services Organization |
| FISO | Field Information Systems Organization |
| FISO | Fit In Stand Out Leadership |
| FISO | First In, Second Out (accounting) |
| FISO | Find, Identify, Select, Obtain (library cataloging) |
| FISO | Functie Informatiesysteem Overheid (Dutch: Function Information System Civil Service) |