IFOS
| Acronym | Definition |
|---|---|
| IFOS | International Festival of the Sea (UK) |
| IFOS | International Fish Oil Standards (Ontario, Canada) |
| IFOS | International Federation of Oto-Rhino-Laryngological Societies (est. 1965) |
| IFOS | International Federation of Ophthalmological Societies (San Francisco, CA) |
| IFOS | Innovative Fiber Optic Solutions (est. 2001; Middletown, OH) |
| IFOS | It's Five O'Clock Somehwere |