- James, the Greater, Saint1
- Jerónima de la Asunción, madre, 1555-16301
- Jesuit drama, Spanish1
- Jiménez de Cisneros, Francisco, 1436?-15171
- John II, King of Aragon, 1397-14791
- Juana, of Austria, Princess of Portugal, 1535-15731
- Jugurthine War (111-105 B.C.)1
- Latin essays1
- Latin language--Study and teaching1
- Latin poetry1
- Law1
- Law commentaries1
- Lectionaries1
- Legal documents1
- Lemos, Pedro Fernández de Castro, conde de, 1576-16221
- Letter of Aristeas1
- León, Luis de, 1527-15911
- Library copies1
- Little office of the Immaculate Conception1
- Lorraine, Nicolas-François, duc de, 1609-16701