IFR (disambiguation)

IFR is instrument flight rules, rules for when flight by outside visual reference is not safe.

IFR may also refer to:

• Infection fatality rate in epidemiology
• Ideal final result, an engineering design goal
• In-flight refueling
• Institute of Food Research, an agricultural and food science research institution
• Integral fast reactor, a nuclear reactor design
• International Federation of Robotics
• International Financing Review, a financial magazine
• International Fleet Review, various publications of the same name
• Instantaneous wave-free ratio (iFR), a diagnostic medical test used in coronary artery stenosis assessment
• Immortals Fenyx Rising, a 2020 video game
• Infield fly rule, a rule in baseball that treats certain balls as caught regardless of outcome