Former Owner
- Monasterio de El Paular1
- Monasterium sanctorum quadraginta martyrum (Treviso Italy)1
- Monastery of Benevívere1
- Monastery of Saint Peter (Erfurt, Germany)1
- Monica Franklyn1
- Monsieur de Bel Air1
- Morot1
- Morris Jastrow, Jr.1
- Morton Davis Mitchell1
- Mount Zion Abbey1
- Mrs. E.J. Hooper1
- Mrs. F. W. Bartlett1
- Mrs. Turnbull1
- Muriel Agnes Fry1
- Murray Anthony Potter1
- Museo Cavaleri1
- N. Pauli1
- Nanna Corbinello1
- Nathan Comfort Starr1
- Nathaniel Dunbar1