Former Owner
- Peter Arrell Brown Widener II2
- Peter Le Neve2
- Philip Hofer2
- Pierleone Leoni2
- Piero Ginori Conti2
- Pierre Gélis-Didot2
- Pierre Pithou2
- Prieuré Saint-Louis de Poissy2
- R. Stora and Company2
- Richard Linenthal2
- Robert Brodhead Honeyman2
- Robert Forrer2
- Ross Winans2
- Rudolf Busch2
- Rush Hawkins2
- Rushton Mather Dorman2
- Sam Fogg Rare Books & Manuscripts2
- Samuel Allen2
- Samuel Claggett Chew2
- San Giorgio Monastery2