Former Owner
- Johann Michael Schiller1
- Johannes Betrus Ravenoldus1
- John Alexander Stewart1
- John Edgar Ker1
- John Lee1
- John Roland Abbey1
- John Ruskin1
- John Ward, 1st Earl of Dudley1
- Juan Burgueño1
- Judith Lady Montefiore College1
- Julian Burgueño1
- Kaikhusroo Minocher Jamaspasa1
- King Lawrence Parker1
- Lathrop Colgate Harper1
- Levi, David, active 19th century1
- London School of Jewish Studies1
- Ludovico Settala1
- Luigi Celotti1
- Luis Fernández de Córdoba y Aragón1
- Maggs Bros Ltd1