| Acronym | Definition |
|---|
| IFR | Instrument Flight Rules (aviation) |
| IFR | International Fleet Review |
| IFR | International Financing Review (Thomson Financial Limited, London, UK) |
| IFR | Institute of Food Research (UK) |
| IFR | Institut Fédératif de Recherche (Research's Federative Institute) |
| IFR | Issue for Review |
| IFR | Inherently Flame Retardant |
| IFR | Interim Final Rule (FDA) |
| IFR | In-Flight Refueling |
| IFR | Instrument Flight Rule |
| IFR | Interim Financial Reporting (accounting) |
| IFR | Integral Fast Reactor (nuclear reactor) |
| IFR | Increasing Failure Rate |
| IFR | Internal Floating Roof (storage tanks) |
| IFR | Interleaved Frame Recording |
| IFR | Industrial Frame Router |
| IFR | Isochronous Frame Reference |
| IFR | Interactive Fax Response |
| IFR | Iris Frame Relay |
| IFR | Ideal Final Result (problem solving) |
| IFR | International Federation of Robotics |
| IFR | Interface Repository (CORBA) |
| IFR | Infrared Receiver |
| IFR | Infield Fly Rule (baseball) |
| IFR | Institute for Fisheries Research |
| IFR | Inspiratory Flow Rate |
| IFR | Institute for Fisheries Resources |
| IFR | Initial Flight Release (aviation) |
| IFR | International Finals Rodeo |
| IFR | Iron Fortified Rice (program; Philippines) |
| IFR | Indoor Firing Range |
| IFR | International Financial Review |
| IFR | International Fellowship of Reconciliation (est. 1919) |
| IFR | Interrupt Flag Register |
| IFR | Instrumented Flux Return |
| IFR | Interleaved Frame Recording (Video) |
| IFR | In Frame Response |
| IFR | In-Flight Report |
| IFR | Institut für Religionspolitologie eV (Duisburg, Germany) |
| IFR | Interior Furniture Resources (Harrisburg, PA) |
| IFR | Induced Field Ratio |
| IFR | Intrinsic Failure Rate (reliability engineering) |
| IFR | Initiative for Fiduciary Responsibility |
| IFR | Insurance and Financial Review (State Farm) |
| IFR | Issued for Review |
| IFR | Institute of Finance Research (Vietnam) |
| IFR | Injury Frequency Ratio (OSHA) |
| IFR | International Fantasy Regulation (Bulwer-Lytton Fiction Contest) |
| IFR | Indirect Fractal Resolution |
| IFR | Integrated Functional Representation |
| IFR | Interference-Fading Resistance |
| IFR | Item for Review |
| IFR | Instant Failure Rate |