Former Owner
- Nathaniel G. Snelling1
- Nettie Goldsmith Naumburg1
- Neustift Abbey1
- Neuwerk Nunnery1
- Niccolò Albergati1
- Nicholas Bacon1
- Nicolai Briganti1
- Nicolas Antoine Labbey de Billy2
- Nicolas Moreau1
- Nicolaus de Monte Murro1
- Octave Chavaillor1
- Oric Bates2
- Orlandus de Fatiis1
- Otto Ege1
- Otto Vollbehr1
- Owen D. Young1
- P. Desq1
- P. Pigeot1
- Paolo Guerrini1
- Paolo Vimercati Sozzi1