Former Owner
- Leicester Harmsworth1
- Leonardus Martinotius1
- Lionel Tollemache, 4th Earl of Dysart1
- Llewelyn Lloyd-Mostyn, 3rd Baron Mostyn of Mostyn1
- London School of Jewish Studies1
- Luigi Cora1
- L’Art Ancien1
- M. Haimmiller1
- Madyājñika Devakṛṣṇa1
- Maggs Bros Ltd1
- Malachia Ormanian1
- Manūchihr Nukhastīn Āṣaf Qājār1
- Margaret Barclay Wilson1
- Matteo Luigi Canonici1
- Mazliah Finzi1
- Melk Abbey1
- Michel Chasles1
- Mistrie, Sita Ram, Pandit1
- Monastery of Benevívere1
- Moritz Dessauer1