Former Owner
- John Harvey Treat1
- John Henry Wrenn1
- John Herbst1
- John Hope, 1st Marquess of Linlithgow1
- John Morgan1
- John Ruskin1
- John Topham1
- John Trotter Brockett1
- John West, 1st Earl De La Warr1
- John Wright1
- Joseph François René de Kergariou1
- Joseph Jekyll1
- Joseph Marie Sormani1
- Josephine Widener Wichfield1
- Julie de Busnel1
- Justin MacCarthy Reagh1
- Lady Margaret Ayloffe1
- Lambertus Eerens1
- Latham family1
- Lathrop C. Harper, Inc.1