Former Owner
- Josiah H. Benton1
- José Antonio Conde1
- José Fernando Ramírez3
- Juan Antonio de la Reguera1
- Juan de Aillon1
- Juan de Torquemada1
- Judith Lady Montefiore College1
- Jules Bonhomme1
- Julie de Busnel1
- Julius Heinrich Jeidels1
- Julius Hess1
- Julius de Cardelinis1
- Justin MacCarthy Reagh1
- Jérôme Bignon1
- Jérôme Pichon1
- K-L1
- K. B. Starkie1
- Karen L. Gould28
- Karl Anton, Prince of Hohenzollern1
- Karl F. Morrison2