Former Owner
- J. & J. Leighton1
- Jacob Dackomb1
- Jacques Rosenthal1
- James & Mary Lee Tregaskis (Firm)1
- Johan C. Jackson1
- Johannes Patou1
- John A. Savage Jr.1
- John D. Stanitz1
- John Dozier Gordan1
- John Eliot Hodgkin1
- John Estmond1
- John Ives1
- John Lee1
- John Roland Abbey1
- John Ruskin1
- Joseph E. Widener1
- Ludwig Rosenthal1
- Luigi Arrigoni1
- Maggs Bros Ltd1
- Maksymilian Mielzynski1