Former Owner
- Leonardo Bruni1
- Leonardo Lapiccirella2
- Leonardo Loredan1
- Leonardus Martinotius1
- Leonello d'Este, Marquis of Ferrara4
- Leonhardus Cuntius1
- Leopold Gruber1
- Lepeletier de Rosanbo1
- Leslie Hindman1
- Lew David Feldman2
- Lewis L. Gould25
- Librairie Damascène Morgand1
- Librairie Tross1
- Library of the Dominicans of Paris1
- Libreria antiquaria Hoepli14
- Libreria antiquaria Mediolanum1
- Libreria la Bibliofila2
- Liechtenstein State Library1
- Lima Public Library4
- Linda Ehrsam Voigts5