The Expulsion of Jews from Spain was the expulsion of practicing Jews following the Alhambra Decree in 1492, which was enacted to eliminate their influence on Spain's large converso population and to ensure its members did not revert to Judaism. Over half of Spain's Jews had converted to Catholicism as a result of the Massacre of 1391. Due to continuing attacks, around 50,000 more had converted by 1415. Many of those who remained decided to convert to avoid expulsion. As a result of the Alhambra decree and the prior persecution, over 200,000 Jews converted to Catholicism, and between 40,000 and 100,000 were expelled. An unknown number returned to Spain in the following years. The expulsion led to mass migration of Jews from Spain to Italy, Greece, Turkey and the Mediterranean Basin. One result of the migration was new Jewish surnames appearing in Italy and Greece. The surnames Faraggi, Farag and Farachi, for example, originated from the Spanish city of Fraga.

The Alhambra Decree was an edict issued on 31 March 1492, by the joint Catholic Monarchs of Spain ordering the expulsion of practising Jews from the Crowns of Castile and Aragon and its territories and possessions by 31 July of that year. The primary purpose was to eliminate the influence of practising Jews on Spain's large formerly-Jewish converso New Christian population, to ensure the latter and their descendants did not revert to Judaism. Over half of Spain's Jews had converted as a result of the religious persecution and pogroms which occurred in 1391. Due to continuing attacks, around 50,000 more had converted by 1415. A further number of those remaining chose to convert to avoid expulsion. As a result of the Alhambra decree and persecution in the years leading up to the expulsion of Spain's estimated 300,000 Jewish origin population, a total of over 200,000 had converted to Catholicism to remain in Spain, and between 40,000 and 100,000 remained Jewish and suffered expulsion. An unknown number of the expelled eventually succumbed to the pressures of life in exile away from formerly-Jewish relatives and networks back in Spain, and so converted to Catholicism to be allowed to return in the years following expulsion.:17