| Radiata | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>RADIATA |
| Radiolaria | EUKARYA>CHROMALVEOLATA>RHIZARIAE>RADIOLARIA |
| Raphidiophyta | EUKARYA>CHROMALVEOLATA>HETEROKONTAE>RAPHIDIOPHYTA |
| Rhizariae | EUKARYOTA>CHROMALVEOLATA>RHIZARIAE |
| Rhodellophytina | see Rhodophyta |
| Rhodophyta | EUKARYA>ARCHAEPLASTIDA>RHODOPLANTAE>RHODOPHYTA |
| Rhodoplantae | EUKARYA>ARCHAEPLASTIDA>RHODOPLANTAE |
| Rhombozoa | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>METAZOA>BILATERIA>PROTOSTOMATA>SPIRALIA>TROCHOZOA>EUTROCHOZOA>RHOMBOZOA |
| Rhyniophyta | EUKARYA>ARCHAEPLASTIDA>VIRIDIPLANTAE>STREPTOBIONTA>EMBRYOPHYTA>TRACHEOPHYTA>RHYNIOPHYTA |
| Rhyniopsida | see Rhyniophyta |
| Rotifera | see Syndermata |