| Acronym | Definition |
|---|
| FEO | Front-End Optimization (computer peformance) |
| FEO | Firearms and Explosives Office (Philippines) |
| FEO | For Each Other (photography group) |
| FEO | Festivals and Events Ontario (Canada) |
| FEO | Iron (II) Oxide (Ferrous Oxide) |
| FEO | Fédération des Enseignantes et Enseignants de l'Ontario (French: Teachers' Federation of Ontario; Ontario, Canada) |
| FEO | Fire Equipment Operator (firefighting) |
| FEO | Faculty Enhancement Opportunity (University of Florida) |
| FEO | Financial Executive Officer (various organizations) |
| FEO | Florida Energy Office |
| FEO | Federal Energy Office |
| FEO | Familial Expansile Osteolysis |
| FEO | For Exhibition Only |
| FEO | Firearms Enquiry Officer (Civilian member of UK police force) |
| FEO | Faculty Education Office (UK) |
| FEO | Funeral Ethics Organization |
| FEO | Find Everything Online (searchable advertising website) |
| FEO | Foederatio Europea Orthodontica (European Federation of Orthodontics) |
| FEO | Flexible Employment Option (various locations) |
| FEO | Fire Engine Operator (California Dept of Forestry and Fire Protection) |
| FEO | Fraternity Education Officer (Phi Mu Alpha) |
| FEO | Facility Emergency Organization |
| FEO | Forcible Entry Operations |
| FEO | Field Engineering Order |
| FEO | Field Engineering Office |
| FEO | Forward Engagement Operations |
| FEO | Flight Elements Office |
| FEO | Fredrick Ernest Osborne (Canadian school) |
| FEO | For the Estate Of |
| FEO | Far East Office |
| FEO | For Friends Eyes Only |
| FEO | Financial Enforcement Office (Phoenix Municipal Court department) |
| FEO | Fuel Efficiency Office (US Air Force Air Mobility Command) |