Former Owner
- John Walker1
- Joseph E. Widener1
- Judith Lady Montefiore College1
- Lancino Curti1
- Lathrop C. Harper, Inc.1
- Laura Hurd Motion1
- Lawrence J. Schoenberg1
- Leonardus Martinotius1
- Leonello d'Este, Marquis of Ferrara1
- Libri, Edoardo, active 20th century1
- Lodovicus Saltariellus1
- Louis Bourguet1
- Louis XII of France1
- Lucien Magne1
- Luigi Arrigoni1
- Luigi Cora1
- Luigi Serra di Cassano1
- M. Favia del Core1
- Mannheimer Hofbibliothek1
- Marcantonio Contarini1