- Patrizi, Francesco, 1275-13281
- Paul, the Deacon, approximately 720-799?1
- Paul, the Hermit, Saint, -approximately 3411
- Pecia1
- Penance (Canon law)1
- Penmanship manuals1
- Persian literature1
- Persian poetry1
- Persius1
- Personal correspondence1
- Peter Martyr, Saint, approximately 1205-12521
- Phalaris, Tyrant of Agrigentum, active 6th century B.C.1
- Phlebotomy1
- Physical appearance of Jesus Christ1
- Physiology1
- Piccinino, Nicolo, -14441
- Piccolomini, Ambrogio Nese1
- Piccolomini, Barna1
- Piccolomini, Caffino di Bartolomeo1
- Piccolomini, Girolamo1