Encyclopedias, Almanacs, Transcripts, and Maps
- rhesus
- Rhinoceroses
- Rhinoceroses (Rhinocerotidae)
- rhodophyte
- Rhombozoa (Rhombozoans)
- rhythm and blues
- Ricci, Matteo
- Richards, Ellen Henrietta Swallow (1842 – 1911) American Chemist
- Richards, Sir Viv
- Richardson, Cyril C.
- richest countries
- Rie, Dame Lucie
- Right Whales and Bowhead Whales (Balaenidae)
- Right-to-Act Legislation
- Right-to-Know
- Ringtail and Greater Gliding Possums (Pseudocheiridae)
- Riparian Land
- Risk Assessment and Management
- Risk Assessors
- Rissh? K?seikai