Former Owner
- Paul Viollet1
- Payne and Foss1
- Payre-Grolée-Virville family1
- Pazzi family1
- Pedro García de Montoya1
- Penzance Library1
- Peter Christos1
- Petrus Giraud1
- Petrus Hofman Peerlkamp1
- Petrus Hofstede1
- Petrus Jensenius1
- Petrus Molitor1
- Petrus Ysermans1
- Petrus de Thureyo1
- Pettini Libraria di Antonio Pettini1
- Philadelphia Rare Books & Manuscripts Company1
- Philibert-Charles-Marie Varenne de Fenille1
- Philip Augustus Hanrott1
- Philip C. Duschnes Rare Books & First Editions1
- Philip Carteret Webb1