Encyclopedias, Almanacs, Transcripts, and Maps
- Royal, Ségolène
- Roycroft Press
- Royo Sánchez, Arístides
- Rozebeke
- Rozhdestvenski, Zinovi Petrovich
- RR Lyrae
- RSFSR
- Ruapehu
- Rub al Khali
- Rubbia, Carlo
- rubeola
- Rubin, Robert Edward
- Rubinstein, Anton Grigoryevich
- Rückert, Friedrich
- rudbeckia
- Rudd, Kevin Michael
- rudderfish
- Rudenstine, Neil Leon
- Rüdesheim
- Rudinì, Antonio Starrabba, marchese di