Former Owner
- Philippe de Béthune1
- Phillip J. Pirages Fine Books & Manuscripts2
- Phyllis Walter Goodhart Gordan8
- Pierre Gélis-Didot1
- Pierre Pithou1
- Pierre de La Vacherie1
- Pietro1
- Pietro Antonio Crevenna1
- Pietro Bembo1
- Pietro Giometti1
- Pius VI1
- Poblet Monastery1
- Poor Clares1
- Prince Augustus Frederick, Duke of Sussex3
- Prospero Caffarelli1
- Pugliese1
- Québriac family1
- R. A. Godwin-Austen1
- R. H. Fenn1
- R. Stora and Company1