Former Owner
- John Savile1
- John Singer Sargent1
- Joseph Anton Koch1
- Joseph L. Lilly1
- Joseph Whitney1
- Joseph-Félix Allard1
- José Antonio Conde1
- Julius Heinrich Jeidels1
- Julius Hess1
- Jérôme Bignon1
- Kartause Erfurt1
- Lambach Abbey1
- Lane Theological Seminary1
- Lathrop C. Harper, Inc.1
- Laurence Kirby1
- Laurentius van der Torqel1
- Leonard Grey, 1st Viscount Grane1
- Leonello d'Este, Marquis of Ferrara1
- Libreria la Bibliofila1
- Libri, Edoardo, active 20th century1