Former Owner
- Joannes Angelus de Crema1
- Johan Meerman1
- Johann Heinrich von Speyr-Passavant1
- Johannes Betrus Ravenoldus1
- John C. Jackson1
- John Lee1
- John Thomas Beer1
- Julius de Cardelinis1
- Lancino Curti1
- Laurence William Hodson1
- Levi, David, active 19th century1
- London School of Jewish Studies1
- Mario Maffei1
- Mazliah Finzi1
- Melk Abbey1
- Michael Bernays1
- Michel Chasles1
- Monastero di Santo Spirito in Verona1
- Moritz Dessauer1
- Morris Jastrow, Jr.1