Former Owner
- Maggs Bros Ltd1
- Manuel Fernández del Castillo3
- Margaret of Croy1
- Mark Lansburgh1
- Marvin-L. Colker2
- Mary Bloch1
- Mary Schell Collins1
- Mary Talbot, Countess of Shrewsbury1
- Matteo Luigi Canonici2
- Michel de Léon1
- Milton Fischmann21
- Mirmellus Arnandi1
- Moissac Abbey1
- Mortimer Loeb Schiff1
- Morton Davis Mitchell1
- Muriel Agnes Fry1
- Nathaniel Sherman Bouton1
- Newman F. McGirr1
- Nicholas B. Scheetz2
- Norman H. Strouse3