Former Owner
- Matthew Simpson Parkhurst1
- Matthias Corvinus1
- Mauni, Bālaṃbhaṭa1
- Maurice Johnson1
- Maurice Kann1
- Mayfair Rare Books and Manuscripts1
- Mazliah Finzi1
- Maḥmūd al-Ustādār, d. 1396 or 71
- Menno Hertzberger1
- Mercantile Library Company1
- Merlemont family1
- Meschatin La Faye family1
- Michael Kantakouzenos Şeytanoğlu1
- Michael Krupp1
- Michael Wodhull1
- Michaeliskonvent1
- Michel Chasles1
- Michel Ferdinand d'Albert d'Ailly1
- Michel de Léon1
- Michele Amari1