| Panarthropoda | see Ecdysozoa |
| Pancrustacea | see Arthropoda |
| Parabasala | EUKARYA>EXCAVATA>EUEXCAVATAE>PARABASALA |
| Parazoa | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>PARAZOA |
| Peltaspermopsida | see Pteridospermophyta |
| Petromyzontomorphi | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>BILATERIA>DEUTEROSTOMATA>VERTEBRATA>PETROMYZONTOMORPHI |
| Pezizomycotina | see Ascomycota |
| Phaeophyta | EUKARYA>CHROMALVEOLATA>HETEROKONTAE>PHAEOPHYTA |
| Phoronida | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>METAZOA>BILATERIA>PROTOSTOMATA>LOPHOTROCHOZOA>LOPHOPHORATA>PHORONIDA |
| Pinopsida | see Coniferophyta |
| Pirellae | EUBACTERIA>PROTEOBACTERIAE>PIRELLAE |
| Pirellobacteria | EUBACTERIA>PROTEOBACTERIAE>PIRELLAE>PIRELLOBACTERIA |
| Placodermi | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>BILATERIA>DEUTEROSTOMATA>VERTEBRATA>GNATHOSTOMATA>PLACODERMI |
| Placozoa | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>DIPLOBLASTEA>PLACOZOA |
| Platyhelminthes | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>METAZOA>BILATERIA>PROTOSTOMATA>PLATYZOA>PLATYHELMINTHES |
| Platyzoa | see Spiralia |
| Polypodiopsida | see Pteridophyta |
| Polytrichopsida | see Bryophyta |
| Polyzoa | see Spiralia |
| Porifera | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>PARAZOA>PORIFERA |
| Prasinophyta | EUKARYA>ARCHAEPLASTIDA>VIRIDIPLANTAE>CHLOROBIONTA>PRASINOPHYTA |
| Priapulida | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>BILATERIA>PROTOSTOMATA>ECDYSOZOA>SCALIDOPHORA>PRIAPULA |
| Proamniota | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>BILATERIA>DEUTEROSTOMATA>VERTEBRATA>GNATHOSTOMATA>TETRAPODA>PROAMNIOTA |
| Progymnospermophyta | EUKARYA>ARCHAEPLASTIDA>VIRIDIPLANTAE>STREPTOBIONTA>EMBRYOPHYTA>TRACHEOPHYTA>PROGYMNOSPERMOPHYTA |
| Protamoeba | EUKARYA>UNIKONTA>AMOEBOZOA>AMOEBOZOAE>PROTAMOEBA |
| Proteobacteriae | EUBACTERIA>PROTEOBACTERIAE |
| Pseudociliata | EUKARYA>EXCAVATA>DISCICRISTATAE>PSEUDOCILIATA |
| Psilotopsida | see Pteridophyta |
| Pteraspidomorphi | EUKARYA>UNIKONTA>OPISTHOKONTA>ANIMALIA>BILATERIA>DEUTEROSTOMATA>VERTEBRATA>PTERASPIDOMORPHI |
| Pteridophyta | EUKARYA>ARCHAEPLASTIDA>VIRIDIPLANTAE>STREPTOBIONTA>EMBRYOPHYTA>TRACHEOPHYTA>PTERIDOPHYTA |
| Pteridospermophyta | EUKARYA>ARCHAEPLASTIDA>VIRIDIPLANTAE>STREPTOBIONTA>EMBRYOPHYTA>TRACHEOPHYTA>SPERMOPHYTA>PTERIDOSPERMOPHYTA |
