| I/F/O | In Front Of 
| Others |
| IFO | I Fell Off
| Others |
| IFO | I Finished Object
| Others |
| IFO | Identified Floating Object
| Others |
| IFO | Identified Flowing Objects
| Others |
| IFO | Identified Flying Object
| Others |
| IFO | Identified Flying Objects
| Others |
| IFO | Ifosfamide
| Others |
| IFO | Import Face Off
| Others |
| IFO | In Favour Of
| Others |
| IFO | In Flight Optimization
| Others |
| IFO | In Front Of ....
| Others |
| IFO | Income From Operations
| Others |
| IFO | Independent Fiscal Office
| Others |
| IFO | Independent Football Ombudsman
| Others |
| IFO | Indoor Flying Object
| Others |
| IFO | Industrial Fuel Oil
| Others |
| IFO | Information File
| Others |
| IFO | Information Flight Office
| Others |
| IFO | Inside Flying Object
| Others |
| IFO | Institute of Fermentation Osaka
| Others |
| IFO | Institute of Financial Operations
| Others |
| IFO | Inter Faculty Organization
| Others |
| IFO | Inter File Optimization
| Others |
| IFO | Inter-Faculty Organization
| Others |
| IFO | Interactive Fluid Office
| Others |
| IFO | Intermediate Fuel Oil
| Others |
| IFO | International Field Office
| Others |
| IFO | International Field Offices
| Others |
| IFO | International Financial Organizations
| Others |
| IFO | International Fitness Observatory
| Others |
| IFO | International Friendship Outreach
| Others |
| IFO | Istituti Fisioterapici Ospitalieri
| Others |
| IFO | Ivano Frankovsk, Ukraine
| Others |