RR, Rr or rr may refer to:

Arts and entertainment

* ''RR'' (film), a 2007 experimental film by James Benning * Red Ribbon Army, a fictional army in the ''Dragon Ball'' series * Ruff Ryders Entertainment, a record label and East Coast rap collective * '' Fury from the Deep'' (production code: RR), a 1968 ''Doctor Who'' serial * ''RR'' (EP), a 2023 collaborative EP by Rosalía and Rauw Alejandro * RR, prefix for models of Jackson Rhoads electric guitars commissioned by guitarist Randy Rhoads

Businesses and organizations

* Rashtriya Rifles, an Indian counter-insurgency force * Rational Recovery, an addiction recovery program * Rekords Rekords (logo), an American record label * Rhodesia Regiment, Rhodesian Army unit *

Royal Air Force The Royal Air Force (RAF) is the Air force, air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the World War I, First World War on 1 April 1918, on the merger of t ...

(IATA airline designator) * Richard Rohac (logo), an Austrian art metal firm

Language

* rr (digraph) * Revised Romanization of Korean, the official Korean language romanization system in South Korea * Revised Romanization of Hangeul, the former official Hangeul language romanization system in South Korea

Science and technology

* ITU Radio Regulations * Rapid Refresh (weather prediction), a short-range numerical weather prediction model * Rear-engine, rear-wheel-drive layout, in automotive design * Recoilless rifle

Biology and medicine

* RR, an Rh factor phenotype * "RR", a blood pressure measurement taken with a sphygmomanometer invented by Scipione Riva-Rocci * RR interval (R wave to R wave interval), the inverse of heart rate * Risk ratio, or relative risk, in statistics and epidemiology * Respiratory rate, a vital sign * Roundup Ready, Monsanto line of genetically modified crop seeds

Computing

* Resource record, in the Domain Name System * Round-robin scheduling, an algorithm for coordinating processes in an operating system * Route reflector, a Border Gateway Protocol configuration * rr (debugging), a record and replay debugger for userspace Linux programs * Resurrection Remix OS, a custom Android ROM created by Altan KRK and Varun Date

Sports

* Rajasthan Royals, an Indian Premier League franchise * Ranchi Rhinos, a defunct Hockey India League franchise * Run rate, an average number of runs a batsman (or the batting side) scores in an over of 6 balls in cricket

Transportation

Raritan River Railroad The Raritan River Rail Road was a shortline railroad in Middlesex County, New Jersey, Middlesex County in the U.S. state of New Jersey, Founded in 1888, it was based in South Amboy, New Jersey, South Amboy, from which it ran west as far as Ne ...

(reporting mark: RR) * Buzz (Ryanair) (IATA code: RR), a Polish airline subsidiary of Ryanair Holdings * Regional Road, a class of road in Ontario * Rhodesia Railways, former Zimbabwean railway company * Rhymney Railway, former British railway company *

Rolls-Royce Holdings Rolls-Royce Holdings plc is a British Multinational corporation, multinational aerospace and defence company incorporated in February 2011. The company owns Rolls-Royce, a business established in 1904 which today designs, manufactures and dist ...

(LSE code and logo) ** Rolls-Royce, several companies * RR, a predecessor of the R (New York City Subway service)