Former Owner
- Karen L. Gould3
- Katherine Petersen1
- Katherine Somerset Wyttenbach Fenwick1
- Lathrop C. Harper, Inc.1
- Lathrop Colgate Harper1
- Laurence Claiborne Witten II2
- Laurence Vaux1
- Lawrence J. Schoenberg12
- Leicester Harmsworth1
- Leo Olschki3
- Leo S. Olschki Editore3
- Lew David Feldman1
- Lewis L. Gould2
- Linda Ehrsam Voigts1
- Lisa Kiser2
- Llewelyn Lloyd-Mostyn, 3rd Baron Mostyn of Mostyn1
- Louis Charles Karpinski1
- Louis César de La Baume Le Blanc1
- Louis H. Silver1
- Louis Loewe1