- Odes, Latin (Medieval and modern)1
- Officium pro defunctis (Catholic Church)1
- Ordinatio (Duns Scotus, John)1
- Painted edges1
- Paleography1
- Palimpsests1
- Panel-stamped bindings1
- Papacy1
- Papal legates1
- Part books1
- Paste papers1
- Pastoral poetry1
- Pastoral poetry, Latin1
- Pastoral theology1
- Pastoral theology--Catholic Church1
- Patrizi, Francesco, 1275-13281
- Patronage, Ecclesiastical1
- Paul, the Hermit, Saint, -approximately 3411
- Peace of Westphalia (1648)1
- Pedro IV, King of Aragon, 1319?-13871