Encyclopedias, Almanacs, Transcripts, and Maps
- Rodzianko, Mikhail Vladimirovich
- Roe, Richard
- Roentgen, Wilhelm
- Roger Huntington Sessions
- Roger Penrose
- Rogers, Robert
- Roland L. Freeman
- Roland, Pauline
- Roldán, Luisa Ignacia
- Rolfe, John
- Rolland, Romain (1866–1944)
- Rolle, Esther
- Romaine-la-Prophétesse
- Roman Catholic Church
- Roman Catholics
- Roman Mythology
- Roman Question
- Roman Republic
- Romanesque architecture
- Romania, Relations with