- Lent1
- Library catalogs1
- Liturgical books1
- Logic1
- Lord's Supper1
- Lord's Supper--Catholic Church--History of doctrines1
- Love1
- Majolus, Saint, Abbot of Cluny, approximately 906-9941
- Manuscripts, Catalan1
- Manuscripts, German1
- Manuscripts, Renaissance1
- Manuscripts, Spanish1
- Marina, Saint1
- Marriage--Moral and ethical aspects1
- Massachusetts--Wellesley1
- Maurice, Saint, -approximately 2871
- Maximus, of Turin, Saint, active 4th century-5th century1
- Medicine1
- Meteorology1
- Michael (Archangel)1