Former Owner
- Lehn of Denmark1
- Leicester Harmsworth5
- Leo Olschki5
- Leo S. Olschki Editore7
- Leonard Grey, 1st Viscount Grane1
- Leonardo Bruni1
- Leonardo Lapiccirella1
- Leonardo Loredan1
- Leonello d'Este, Marquis of Ferrara4
- Leopold Gruber1
- Leslie Hindman1
- Leslie, John (c. 1840), bookseller1
- Lew David Feldman1
- Lewis L. Gould17
- Librairie Damascène Morgand2
- Libreria la Bibliofila1
- Libri, Edoardo, active 20th century1
- Liechtenstein State Library1
- Lima Public Library3
- Linda Ehrsam Voigts3