- Pego, Jacobus de1
- Penance (Canon law)1
- Perini, Francesco, 1811-18831
- Pero, Antonio del1
- Pero, Gaspero del1
- Perocti, Maruccio1
- Perpetual calendars1
- Persecution1
- Persecution--Early church1
- Persius1
- Petrini, Mattea1
- Petronibus, Agabitus de1
- Petronibus, Ludovicus Salimbeni de1
- Petronibus, Petronius Caterini de1
- Petronibus, Petronius de1
- Phalaris, Tyrant of Agrigentum, active 6th century B.C.1
- Pharmacognosy1
- Pharmacy1
- Philip III, King of Spain, 1578-16211
- Philosophy, Ancient--Study and teaching1