| Acronym | Definition |
|---|
| FRSO➣Freedom Road Socialist Organization |
| FRSO➣Frankfurt Radio Symphony Orchestra (Germany) |
| FRSO➣Finnish Radio Symphony Orchestra (est. 1927) |
| FRSO➣Fédération Régionale des Sports d'Orientation (South Belgium Orienteering Federation; French) |
| FRSO➣Federal Relay Service Online (federal disability service) |
| FRSO➣Ferret Rescue Society of Ottawa and Area (Ottawa, Canada) |