Former Owner
- Mary Augusta Strachey1
- Mary Schell Collins1
- Mary Talbot, Countess of Shrewsbury1
- Mary W. T. Dickinson1
- Matthaeus Lupin1
- Maurilio Morazio1
- Maximilian Henry of Bavaria1
- Mayer Sulzberger1
- Melchior Daniel Neubronner1
- Merlemont family1
- Michael Bernays1
- Michael M. Zagayski1
- Michiel family1
- Moritz Joseph Johann von Dietrichstein1
- Morris Jastrow, Jr.1
- Mortimer Frank1
- Mortimer Loeb Schiff1
- Mr. Hals1
- Muhsinzâde Ömer Aǧa1
- Musa Kâzım Efendi1