Former Owner
- John F. Fleming1
- John M Cuthbert1
- John Roland Abbey1
- John Swyntoun1
- John Topham1
- John Trotter Brockett1
- John West, 1st Earl De La Warr1
- John Wright1
- Joseph François René de Kergariou1
- Joseph Jekyll1
- Joseph Whitney1
- José Antonio Conde1
- Juan Burgueño1
- Juan de Londono1
- Juana I of Castile1
- Julian Burgueño1
- Julius Hess1
- Justin MacCarthy Reagh1
- Kloster Kuringen1
- Lady Margaret Ayloffe1