Former Owner
- Marianne F. ???1
- Marilyn Carbonell2
- Mario Pedro Arata1
- Mark Augspürger1
- Mark Lansburgh1
- Mark Sittich von Hohenems Altemps1
- Markus Fugger1
- Marquis of Astorga1
- Marsden J. Perry1
- Martin J. Cooper4
- Martin Picker1
- Mary Augusta Strachey1
- Mary Schell Collins1
- Mary Talbot, Countess of Shrewsbury1
- Mary W. T. Dickinson1
- Matteo Luigi Canonici2
- Matthaeus Lupin1
- Maurilio Morazio1
- Maximilian Henry of Bavaria1
- Mayer Sulzberger3