Former Owner
- Marchese Linterno1
- Margaret of Croy1
- Marguerite de Fontenay1
- Marie Ange-Toussaint Placide de Ferron1
- Marie Cleophe de Sollario1
- Marie Thomas1
- Marie de Albano1
- Marie-Caroline of Bourbon-Two Sicilies, Duchess of Berry1
- Marienstiftsgymnasium1
- Marino Grimani1
- Maurice Kann1
- Mayfair Rare Books and Manuscripts1
- Melk Abbey1
- Middle Hill Rare Books & Manuscripts AB (Stockholm, Sweden)1
- Minerva Kaiser1
- Minnis, Katherine1
- Monasterio de El Paular1
- Monsieur de Bel Air1
- Mrs. F. W. Bartlett1
- Muriel Agnes Fry1