Former Owner
- Paolo Gallo1
- Paolo Vimercati Sozzi1
- Paul Gottschalk1
- Paul Sabatier1
- Payne and Foss1
- Peter Christos1
- Peter Eaton1
- Petrus Joseph Puccius1
- Petrus Leonardus1
- Petrus Martinotius1
- Philip Hofer1
- Philip Milburn2
- Phillip J. Pirages Fine Books & Manuscripts3
- Pierleone Leoni1
- Piero Ginori Conti1
- Pietro Civaleri1
- Pietro Dini1
- Pietro Millini1
- Pietro Odescalchi1
- Preston A. Perry2