IRR

IRR or Irr may refer to:

Finance

 * Implied repo rate, in the futures market
 * Internal rate of return, a profitability metric
 * Iranian rial, currency of Iran by ISO 4217 code
 * Interest rate risk, financial risk from fluctuating interest rates

Organisations

 * Incident Response Regiment (Australia), an emergency response agency
 * Institute of Race Relations, a policy institute
 * Institute for Religious Research, an apologetics organization
 * Iraqi Republic Railways, a transportation operator
 * South African Institute of Race Relations, a think tank

Science and technology

 * Image rejection ratio, a radio metric
 * Interrupt Request Register, a register used for managing interrupts in programmable interrupt controllers
 * Internet Routing Registry, a network routing database
 * Irregular galaxy, a galaxy that does not have a distinct regular shape

Other

 * Incidence rate ratio, a statistic derived from a Poisson regression model
 * Individual Ready Reserve, a personnel status of the United States Military
 * Infusion-related reaction or infusion reaction, a form of systemic inflammatory response syndrome caused by some diseases and drugs
 * Inner Ring Road (disambiguation)
 * Inter-rater reliability