PRR

PRR may refer to:


 * Parietal reach region, of the human brain
 * Pattern recognition receptor, receptors of the innate immune system that identify pathogen-associated molecular patterns
 * Pennsylvania Railroad (reporting mark), an American railroad
 * Personal Role Radio, a radio carried by UK troops
 * Pichi Richi Railway, a heritage railway in South Australia
 * Populist radical right, a loose collection of political ideologies
 * Porsche Rennsport Reunion, an automotive event
 * Princes Risborough railway station (National Rail station code), England
 * Production Rule Representation, a proposed computing standard
 * Proportional reporting ratio, a statistic used in data mining for health surveillance systems
 * Pseudo-response regulator, a group of genes that are important in the circadian oscillator of plants
 * Pure Reason Revolution, a British rock group formed in 2003
 * Rio-grandense Republican Party (Portuguese: Partido Republicano Rio-Grandense), a defunct Brazilian political party