The Tribunal of the Holy Office of the Inquisition (Spanish: Tribunal del Santo Oficio de la Inquisicion); commonly known as the Spanish Inquisition (Inquisicion espanola); was established in 1478 by Catholic Monarchs Ferdinand II of Aragon and Isabella I of Castile.

The Inquisition was originally intended primarily to ensure the orthodoxy of those who converted from Judaism and Islam. The regulation of the faith of the newly converted was intensified after the royal decrees issued in 1492 and 1502 ordering Jews and Muslims to convert or leave Spain.

The Inquisition was not definitively abolished until 1834; during the reign of Isabella II; after a period of declining influence in the preceding century.