- Ospedale degli Innocenti (Florence, Italy)1
- Otto I, Holy Roman Emperor, 912-9731
- Outlines and syllabi1
- Ovando, Nicolás de, approximately 1460-15111
- Oviedo family1
- Oviedo, Francisco de, 1728-1
- Oviedo, Gregorio de, 1721-17961
- Oviedo, Nicolás de, 1725-1
- Paganelli, Roberto1
- Pain--Religious aspects--Christianity1
- Painted books1
- Pakhomiĭ Logofet, monk, active 15th century1
- Pakistan--Wazīrābād1
- Palm-leaf manuscripts1
- Palmistry1
- Pamphlets1
- Panama--Panama1
- Pandnāmah (ʻAṭṭār, Farīd al-Dīn)1
- Paolo, Stefano di1
- Papal legates1