Former Owner
- John Towneley1
- John Trotter Brockett1
- John William Harshberger1
- Jonathan Peckover1
- Joseph François René de Kergariou1
- Joseph Görres1
- Joseph Pope1
- Joseph Whitney1
- José Antonio Conde1
- Juana I of Castile1
- Judah ben Moses, ha-Rofe, ha-Kohen1
- Julius Hess1
- Jérôme Bignon1
- K. B. Starkie1
- Kenneth Hyde1
- Kloster Rebdorf1
- Kulturhistorisches Museum Magdeburg1
- Lajos Graf Apponyi de Nagy-Appony1
- Latham family1
- Lathrop C. Harper, Inc.1