Former Owner
- Minnis, Katherine1
- Miriam Lutcher Stark3
- Mirmellus Arnandi1
- Moissac Abbey1
- Molin1
- Monasterio de El Paular1
- Monasterium sanctorum quadraginta martyrum (Treviso Italy)1
- Monastery of Benevívere1
- Monastery of Saint Peter (Erfurt, Germany)1
- Monastery of San Bartolmeo, Arezzo, Tuscany1
- Monica Franklyn1
- Monsieur de Bel Air1
- Moor of Ireton1
- Morot1
- Morris H. Morgan5
- Morris Jastrow, Jr.1
- Mortimer Frank1
- Morton Davis Mitchell1
- Mount Zion Abbey1
- Mr. Hals1