Former Owner
- Oliver R. Barrett1
- Orlandus de Fatiis1
- Oswald Carl Friedrich von Seilern und Aspang1
- Owen D. Young1
- Pangracius Chrewczer1
- Paolo Gallo1
- Parroco di Taviano, Luigi Bruno, active 20th century1
- Paul Joseph Sachs1
- Paul Louis Feiss1
- Paul de Berthou1
- Pauline Fore Moffitt1
- Paulus de Graecus1
- Pazzi family1
- Pease, John William, 1820-19001
- Pedro García de Montoya1
- Peter Arrell Brown Widener1
- Peter Ludwig1
- Petrus Hofstede1
- Petrus Jensenius1
- Petrus Ysermans1