Former Owner
- Maurice Kann1
- Maurilio Morazio1
- Mayfair Rare Books and Manuscripts1
- Mercantile Library Company1
- Meschatin La Faye family1
- Michael Wodhull1
- Mikhail Golitsyn1
- Millard Meiss1
- Molin1
- Moritz Joseph Johann von Dietrichstein1
- Murray Anthony Potter1
- Nathaniel Sherman Bouton1
- Nettie Goldsmith Naumburg1
- Niccolò Albergati1
- Nicolas Antoine Labbey de Billy1
- Norman H. Strouse1
- Novalesa Abbey1
- Oliver Henry Perkins1
- Omaha Public Library1
- Orlandus de Fatiis1