Former Owner
- Maksymilian Mielzynski1
- Marchese Porri-Carcani1
- Margaret Le Seigneur1
- Margaret of Croy1
- Marguerite of Lorraine1
- Mary Schell Collins1
- Mary Talbot, Countess of Shrewsbury1
- Matteo Luigi Canonici1
- Mercantile Library Company1
- Messieurs Du Trieu2
- Milton Fischmann5
- Minnis, Katherine1
- Morot1
- Morris Harold Saffron1
- Mortimer Loeb Schiff1
- Muriel Agnes Fry1
- Muḥammad Shams al-Dīn Naqshband Nūrī1
- N. Pauli1
- Nathaniel Sherman Bouton1
- Nicholas B. Scheetz1