Former Owner
- Miguel de Mayora1
- Mikhail Golitsyn1
- Millard Meiss1
- Milt Freudenheim1
- Minerva Kaiser1
- Minnis, Katherine1
- Molin1
- Monastery at San Gregorio al Celio1
- Monica Franklyn1
- Monsieur de Bel Air1
- Morell Thurston1
- Moritz Dessauer1
- Morot1
- Mrs. E.J. Hooper1
- Muriel Agnes Fry1
- Murray Anthony Potter1
- N. Pauli1
- Nancy McGrath1
- Nanna Corbinello1
- Nathaniel Sherman Bouton1