Former Owner
- Juana I of Castile1
- Julian Burgueño1
- Julius Hess1
- Justin MacCarthy Reagh1
- Katherine Petersen1
- King Lawrence Parker1
- Kloster Kuringen1
- Konrad von Maurer1
- Lady Margaret Ayloffe1
- Lajos Graf Apponyi de Nagy-Appony1
- Latham family1
- Laurent Campagne1
- Laurentius van der Torqel1
- Legoué1
- Leicester Harmsworth1
- Leonardo Lapiccirella1
- Librairie Damascène Morgand1
- Libreria antiquaria Mediolanum1
- Libreria la Bibliofila1
- Libri, Edoardo, active 20th century1