Former Owner
- Libri, Edoardo, active 20th century1
- Lisa Norris Elkins1
- Louis Bourguet1
- Lydia Thompson Morris1
- Maksymilian Mielzynski1
- Marchese Porri-Carcani1
- Margaret F. Woodward1
- Margaret Le Seigneur1
- Margaret of Croy1
- Marguerite de Belleville1
- Marguerite de Fontenay1
- Marguerite of Lorraine1
- Marie Ange-Toussaint Placide de Ferron1
- Marion Lawrence1
- Martinus Nijhoff1
- Middle Hill Rare Books & Manuscripts AB (Stockholm, Sweden)1
- Milt Freudenheim1
- Milton S. Carothers1
- Minnis, Katherine1
- Monsieur de Bel Air1