| revocare | abolish |
| Revolution | Revolution |
| revolver | gun |
| revolver a sei colpi | six-shooter |
| revulsivo | revulsive |
| REX | Rex |
| Rex Sacrorum | Sacred king |
| Rex Stout | Rex Stout |
| Rexhep Meidani | Rexhep Meidani |
| Rexismo | Rexism |
| Rey Mysterio | Oscar Gutierrez |
| Reykjahlid | Reykjahlíð |
| Reykjanes | Reykjanes |
| Reykjanesbær | Reykjanesbær |
| Reykjavik | Reykjavik |
| Reykjavík | Reykjavík |
| Reyðarfjörður | Borgarfjörður |
| Reza Abbasi | Reza Abbasi |
| Reza Pahlavi | Reza Shah |
| Reziario | Retiarius |
| Rezina | Raionul Rezina |
| Rešov | Rešov |
| RF | RF |
| RFI SpA | Rete Ferroviaria Italiana |
| RFLP | Restriction fragment length polymorphism |
| RG | RG |
| RG Veda | RG Veda |
| RGB | RGB color model |
| Rh | Rh factor |
| Rhabdodontidae | Rhabdodontidae |
| Rhamphorhynchus | Rhamphorhynchus |
| Rhaphigaster nebulosa | Rhaphigaster nebulosa |
| Rhapsody of Fire | Rhapsody of Fire |
| Rhazes | Muhammad ibn Zakarīya Rāzi |
| Rhea | Rhea |
| Rhea americana | Rhea |
| Rheae | Rhea |
| Rheidae | Rhea |
| Rhein-Erft-Kreis | Rhein-Erft-Kreis |
| Rhein-Neckar-Kreis | Rhein-Neckar-Kreis |
| Rheinau | Rheinau |
| Rheineck | Rheineck |
| RheinEnergieStadion | RheinEnergieStadion |
| Rheingau | Rheingau wine |
| Rheingau-Taunus-Kreis | Rheingau-Taunus-Kreis |
| Rheingold Express | Rheingold Express |
| Rheinhausen | Rheinhausen |
| Rheinhessen | Rhenish Hesse |
| Rheinisch-Bergischer Kreis | Rheinisch-Bergischer Kreis |
| Rheinmünster | Rheinmünster |
| Rheinpark Stadion | Rheinpark Stadion |
| Rheinstetten | Rheinstetten |
| Rheintal | Rheintal |
| RHESSI | Reuven Ramaty High Energy Solar Spectroscopic Imager |
| Rheum | Rhubarb |
| Rhinebeck | Rhinebeck |
| Rhino Records | Rhino Entertainment |
| Rhinoceros | Rhinoceros |
| Rhinoceros sondaicus | Javan Rhinoceros |
| Rhinoceros unicornis | Indian Rhinoceros |
| Rhinocerotidae | Rhinoceros |
| rhinocéros noir | black rhinoceros |
| Rhinolophus | Rhinolophus |
| Rhinos Milano | Rhinos Milano |
| Rhipsalis | Rhipsalis |
| Rhizobium | Rhizobia |
| Rhizophorales | Rhizophoraceae |
| Rhizostomeae | Rhizostomae |
| Rho | Rho |
| Rho Cassiopeiae | Rho Cassiopeiae |
| Rhode Island | Rhode Island |
| Rhodesia | Rhodesia |
| Rhodesian Ridgeback | Rhodesian Ridgeback |
| Rhodophyta | Red algae |
| Rhodri Mawr ap Merfyn | Rhodri the Great |
| Rhombozoa | Rhombozoa |
| Rhona Mitra | Rhona Mitra |
| Rhondda Cynon Taff | Rhondda Cynon Taff |
| Rhun ap Maelgwn | Rhun Hir ap Maelgwn |
| Rhyaciano | Rhyacian |
| Rhynchocyon chrysopygus | Golden-rumped Elephant Shrew |
| Rhynchophorus ferrugineus | Rhynchophorus ferrugineus |
| Rhynchosauria | Rhynchosaur |
| Rhynchota | Hemiptera |
| Rhynchotus rufescens | Red-winged Tinamou |
| Rhynochetos jubatus | Kagu |
| Rhys ap Gruffydd | Rhys ap Gruffydd |
| Rhys ap Tewdwr | Rhys ap Tewdwr |
| Rhythm and blues | Rhythm and blues |
| Rhythm of the Saints | The Rhythm of the Saints |
| Rhythmophone | Rhythmophone |
| Rhäzüns | Rhäzüns |
| Rhêmes-Saint-Georges | Rhêmes-Saint-Georges |
| Rhön-Grabfeld | Rhön-Grabfeld |
| RI | RI |
| ri-mobilizzazione degli inquinanti | pollutant remobilisation |
| RIAA | Recording Industry Association of America |
