Former Owner
- Merlemont family1
- Meschatin La Faye family1
- Michael Wodhull1
- Michaeliskonvent1
- Michel Chasles1
- Michel Ferdinand d'Albert d'Ailly1
- Michel Guibé1
- Michel de Léon1
- Middle Hill Rare Books & Manuscripts AB (Stockholm, Sweden)1
- Miguel de Mayora1
- Mikhail Golitsyn1
- Millard Meiss1
- Milt Freudenheim1
- Milton S. Carothers1
- Minerva Kaiser1
- Minnis, Katherine1
- Mirmellus Arnandi1
- Moissac Abbey1
- Molin1
- Monasterio de El Paular1