- Sancho II, King of Castile and Leon, 1037 or 1038-10721
- Sarmiento, Pero. Sentencia-Estatuto1
- Satire1
- Satires1
- Science1
- Sea fiction1
- Sea stories, Spanish1
- Sententiarum libri IV (Peter Lombard, Bishop of Paris)1
- Sepúlveda, Juan Ginés de, 1490-15731
- Sermons, Spanish1
- Service books (Music)--Catholic Church1
- Seven Years' War (1756-1763)1
- Shipping1
- Silva, Juan de, Conde de Cifuentes1
- Sonnets1
- Spain--Alcalá de Henares1
- Spain--Burgos1
- Spain--Covadonga1
- Spain--Cuenca1
- Spain--Cuenca (Province)1