- Malatesta, Sigismondo Pandolfo, signore di Rimini, 1417-14681
- Mancini, Girolamo, 1832-19241
- Manuscripts, Greek (Medieval and modern)1
- Maps1
- Marbled paper bindings1
- Marriage1
- Marriage (Canon law)1
- Marriage (Canon law)--Dispensations1
- Martellini, Vincenzio1
- Martini, Giovanni1
- Marucelli, Benedetto1
- Marucelli, Francesco, 1625-17031
- Mary, Queen of Scots, 1542-15871
- Medical education1
- Medici, Bastiano de'1
- Medici, Carlo Bernardo Alamanni de'1
- Medici, Elisabetta de'1
- Medici, Fernando de'1
- Medici, Francesca de'1
- Medici, Giulio de'1