- Manuscripts, Spanish1
- Maps1
- Marbled paper bindings1
- Marginalia1
- Martini, Luca, 1980-1
- Marucelli, Benedetto1
- Marucelli, Francesco, 1625-17031
- Mary, Queen of Scots, 1542-15871
- Massachusetts--Williamstown1
- Mathematical recreations1
- Maurice, Saint, -approximately 2871
- Maximian, Emperor of Rome, approximately 240-3101
- Medea, consort of Aegeus, King of Athens (Mythological character)1
- Medical education1
- Medici, Bastiano de'1
- Medici, Bernardo d'Alamanno de'1
- Medici, Fernando de'1
- Medici, Giuliano de', 1453-14781
- Medici, Nicolo de'1
- Medici, Piero di Lorenzo de', 1472-15031