- James, the Greater, Saint1
- Jesuit drama, Spanish1
- Jewish illumination of books and manuscripts1
- John I, King of Portugal, 1357-14331
- Juana, of Austria, Princess of Portugal, 1535-15731
- Lacquered bindings1
- Laudatory poetry, Latin1
- Lemos, Pedro Fernández Ruiz de Castro y Osorio, conde de, active 17th century1
- Lyric poetry1
- Majnūn Laylá1
- Manners and customs1
- Manuscripts, Galician1
- Manuscripts, Renaissance1
- Margarita, de Austria, Queen, consort of Philip III, King of Spain, 1584-16111
- Martyrdom1
- Martyrs1
- Mary, Blessed Virgin, Saint1
- Masnavis, Persian1
- Mathematics1
- Mezuzah1