Former Owner
- Paolo Giovio1
- Paolo Vimercati Sozzi1
- Parroco di Taviano, Luigi Bruno, active 20th century1
- Patrick Brady1
- Paul Gottschalk1
- Paul Sabatier1
- Payne and Foss1
- Peter Christos1
- Peter Eaton1
- Peter Ludwig1
- Petrus Joseph Puccius1
- Petrus Leonardus1
- Petrus Martinotius1
- Petrus de Thureyo1
- Pettini Libraria di Antonio Pettini1
- Philip Hofer1
- Philip Milburn3
- Phillip J. Pirages Fine Books & Manuscripts3
- Phyllis Walter Goodhart Gordan5
- Pierleone Leoni1