Former Owner
- Joseph Barrois3
- Josh Miller1
- Julius Bisno1
- Jérôme Bignon1
- K. B. Starkie1
- 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