- Peter Lombard, Bishop of Paris, approximately 1100-11601
- Peter Martyr, Saint, approximately 1205-12521
- Petrarca, Francesco, 1304-13742
- Petrini, Mattea1
- Petronibus, Agabitus de1
- Petronibus, Ludovicus Salimbeni de1
- Petronibus, Petronius Caterini de1
- Petronibus, Petronius de1
- Petrucci, Pandolfo, 1452-15122
- Phaedra (Greek mythological character)1
- Phalaris, Tyrant of Agrigentum, active 6th century B.C.2
- Phanariots1
- Pharmacognosy1
- Pharmacology1
- Pharmacopoeias1
- Pharmacy2
- Pharmacy--Study and teaching1
- Pharsalia (Lucan)1
- Philanthropists1
- Philip II, King of Macedonia, 382 B.C.-336 B.C.1