Former Owner
- John Couch Adams1
- John Eliot Hodgkin1
- John F. Fleming1
- John Gribbel1
- John Harrison-Broadley1
- John Hindley1
- John Hirst1
- John Hope, 1st Marquess of Linlithgow1
- John Morgan1
- John Shelton Lawrence1
- John Walker1
- Joseph E. Widener1
- Julius Hess1
- Kenneth Hyde1
- Lajos Graf Apponyi de Nagy-Appony1
- Lathrop C. Harper, Inc.1
- Libri, Edoardo, active 20th century1
- Llewelyn Lloyd-Mostyn, 3rd Baron Mostyn of Mostyn1
- Lodovicus Saltariellus1
- Louis Bourguet1