- R. Paul ButlerCitizenship: United StatesBorn: 1960
- Raphael M. RobinsonCitizenship: United StatesBorn: November 2, 1911
- Regina PodstanickáCitizenship: SlovakiaBorn: March 25, 1928
- Remo SaraceniBorn: January 15, 1935Occupation: sculptor
- René de Saint-PérierCitizenship: FranceBorn: August 18, 1877
- Rex CowanCitizenship: United KingdomBorn: June 16, 1927
- Ricardo Becerro de BengoaCitizenship: SpainBorn: February 7, 1845
- Richard G. DavisCitizenship: United StatesBorn: 1950
- Richard PocockeCitizenship: Kingdom of Great BritainBorn: November 19, 1704
- Richard von KaufmannCitizenship: German EmpireBorn: March 29, 1849
- Richard WatersCitizenship: United StatesBorn: September 19, 1935
- Richard William Howard VyseCitizenship: Kingdom of Great BritainBorn: July 25, 1784
- Robert von LiebenCitizenship: Austria–HungaryBorn: September 5, 1878
- Roman GhirshmanCitizenship: FranceBorn: October 15, 1895
- Rudolf DieselCitizenship: Kingdom of BavariaBorn: March 18, 1858
- Rudolf Ferdinand SpitalerCitizenship: AustriaBorn: January 7, 1859