- Otto I, Holy Roman Emperor, 912-9731
- Ovando, Nicolás de, approximately 1460-15111
- Oviedo family1
- Oviedo, Francisco de, 1728-1
- Oviedo, Gregorio de, 1721-17961
- Oviedo, Nicolás de, 1725-1
- Pacheco de Silva, Juana1
- Painted books1
- Palomino family1
- Panama--Panama1
- Papacy1
- Papal documents1
- Passion of Jesus Christ19
- Patriotism1
- Peace of Westphalia (1648)1
- Pedro I, King of Castile and Leon, 1334-13691
- Pedro IV, King of Aragon, 1319?-13871
- Pelayo, King of Asturias, -7372
- Penance1
- Penmanship1