Author
- Ottavio Strada1
- Ottmar Luscinius1
- Otto III1
- Otto di guardia e balia (Florence, Tuscany)1
- Otto of Passau1
- Pacholo Falconieri1
- Pakudha Kaccayana1
- Palazzo degli Anziani1
- Papias1
- Paramahaṃsa Parivrājaka1
- Paramahaṃsa Vrājakācārya1
- Paramaśivāśrama1
- Paraśurāma1
- Parliament of Great Britain1
- Paschal II1
- Paschualis Bernardus1
- Patrick Graham, 1st Lord Graham1
- Paul IV1
- Paul of Aegina1
- Paul the Deacon1