Former Owner
- Jacob Henry Burn1
- Jacob Riegel1
- James H. Stewart1
- Jay Gould1
- Jesuit College of San Bartolomeo1
- Joachim Guerrinus de Montefegatesio1
- Joannes Angelus de Crema1
- Johan Meerman1
- Johann Heinrich von Speyr-Passavant1
- John C. Jackson1
- John Lee1
- John Thomas Beer1
- Julius de Cardelinis1
- Lancino Curti1
- Lathrop C. Harper, Inc.1
- Lathrop Colgate Harper1
- Laurence Claiborne Witten II1
- Laurence William Hodson1
- Leonardo Loredan1
- Leonello d'Este, Marquis of Ferrara1