Former Owner
- Marie-Caroline of Bourbon-Two Sicilies, Duchess of Berry1
- Marino Grimani1
- Mariota Lyle1
- Martinus Nijhoff1
- Mathias Schurer1
- Matteo Barresi1
- Matthew Simpson Parkhurst1
- Matthias Corvinus1
- Maurice Kann1
- Maxwell Sommerville1
- Michael Wodhull1
- Michaeliskonvent1
- Michel de Léon1
- Michele Amari1
- Middle Hill Rare Books & Manuscripts AB (Stockholm, Sweden)1
- Mikhail Golitsyn1
- Millard Meiss1
- Minerva Kaiser1
- Minnis, Katherine1
- Molin1