Former Owner
- Lathrop C. Harper, Inc.1
- Laurence Kirby1
- Laurentius van der Torqel1
- Leonard Grey, 1st Viscount Grane1
- Libri, Edoardo, active 20th century1
- Llewelyn Lloyd-Mostyn, 3rd Baron Mostyn of Mostyn1
- Loftus Bland1
- Louis II, Count of Flanders1
- Lucien Magne1
- Lucrezio Palladio degli Olivi1
- Ludwig Rosenthal's Antiquariaat1
- Luigi Arrigoni1
- Luigi Celotti1
- Luigi Clerici1
- Luis Mayora1
- Léon Gruel1
- Léon Techener1
- Magby, H1
- Marchese Linterno1
- Margaret of Croy1