Former Owner
- John Camp Williams1
- John D. Stanitz1
- John Eliot Hodgkin1
- John Fenn1
- John Hinsdale Scheide1
- John Holt1
- John Sidney Hawkins1
- John Sotheby1
- Joseph Anton Koch1
- Joseph L. Lilly1
- Joseph Mayner1
- Judith Lady Montefiore College1
- Konrad von Maurer1
- Lancino Curti1
- Laurence Kirby1
- Law Society1
- Leicester Harmsworth1
- Leonard Grey, 1st Viscount Grane1
- Lionardo di Paolo Adimari1
- Lodovicus Saltariellus1