RR

RR, Rr or rr may refer to:

Arts and media

RR (film), a 2007 experimental film by James Benning
Red Ribbon Army, a fictional army in the Dragon Ball series
Reference Reviews, a journal on reference works
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

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

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, a Monsanto line of genetically modified crop seeds

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

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

RR, a predecessor of the R (New York City Subway service)
Raritan River Railroad (reporting mark: RR)
Buzz (Polish airline) (IATA code: RR), a Polish airline subsidiary of Ryanair Holdings
Rhodesia Railways, former Zimbabwean railway company
Rhymney Railway, former British railway company
Royal Air Force (IATA airline designator RR)