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