Former Owner
- Otto Ege1
- Owen D. Young1
- P. Pigeot1
- Parroco di Taviano, Luigi Bruno, active 20th century1
- Paul Gottschalk1
- Paul Louis Feiss1
- Paul Riant1
- Paul Sabatier1
- Peter Arrell Brown Widener1
- Petrus Hofstede1
- Petrus Jensenius1
- Petrus Ysermans1
- Philadelphia Rare Books & Manuscripts Company1
- Philip Hofer1
- Philip Kerr, 11th Marquess of Lothian1
- Philippe de Béthune1
- Pierre Pithou1
- Pietro1
- Pietro Bembo1
- Pietro Giometti1