Former Owner
- Joseph Jekyll1
- Juan Burgueño1
- Juan de Londono1
- Julian Burgueño1
- Justin MacCarthy Reagh1
- Katherine Petersen1
- King Lawrence Parker1
- Kloster Kuringen1
- Konrad von Maurer1
- Lady Margaret Ayloffe1
- Lajos Graf Apponyi de Nagy-Appony1
- Latham family1
- Laurent Campagne1
- Legoué1
- Leicester Harmsworth1
- Lionel Tollemache, 4th Earl of Dysart1
- Lisa Norris Elkins1
- Little family1
- Llewelyn Lloyd-Mostyn, 3rd Baron Mostyn of Mostyn1
- Long Island Historical Society, Maine1