HRR

HRR may refer to:


 * Haploid-relative-risk, a method for determining gene allele association to a disease
 * Hardy, Rand & Rittler pseudoisochromatic plates, a type of color vision test
 * Harrington railway station, in England
 * Henley Royal Regatta
 * Healy River Airport, in Alaska, United States
 * Heart rate reserve
 * Hirzebruch–Riemann–Roch theorem
 * Historicorum Romanorum reliquiae, a collection of ancient fragmentary Latin history-works
 * The History of Rock and Roll, a radio documentary
 * Holy Roman Empire (German: Heiliges Römisches Reich)
 * Homologous recombination repair, a major DNA repair pathway that mainly acts on double-strand breaks and interstrand crosslinks
 * Hondo Railway, an American railway
 * Horuru language, spoken in Indonesia