F/O
| Acronym | Definition |
|---|---|
| F/O | Find Out |
| F/O | Father Of |
| F/O | Forward Observer (artillery) |
| F/O | Fiber-Optic |
| F/O | First Officer |
| F/O | Fictional Other (online chat) |
| F/O | Front Office |
| F/O | Foldout |
| F/O | Flight Officer |
| F/O | Full Option (automobiles) |
| F/O | Farm-Out (oil & gas) |
| F/O | Fuel to Oxidizer Ratio |