History of the Catholic Church in Spain

The Catholic Church in Spain has a long history, starting in the 1st century AD. It is the largest religious group in the country, with 58.6% of Spaniards identifying as "Catholic".

Attempts were made from the late 1st century to the late 3rd century to establish Christianity in the Iberian Peninsula. Paul the Apostle expressed a wish to preach in Spain in the Epistle to the Romans; Clement of Rome writes in his Epistle to the Corinthians that Paul "travelled as far as the extremity of the West," and the Muratorian Canon also speaks of Paul having departed from Rome for Spain. Although most scholars of early Christianity believe Paul did not make an actual journey to Spain after writing the Epistle to the Romans, Jerome Murphy-O'Connor holds that Paul did travel to Spain and preach there for up to a few months with little success, most likely because Greek was not widely spoken there. Timothy D. Barnes suggests that Paul's trial and execution took place not in Rome as traditionally believed, but under a provincial governor in Spain. Traditional accounts credit the Apostle James the Great with early preaching of the Christian faith in Spain.

Canons of the Synod of Elvira (circa 305 AD in Rome) indicate that the church was greatly isolated from the general population even at that time. The situation of the Christians in Iberia improved with the advent of the Edict of Milan in 313 AD, after which Christians were more or less free to openly practice their new religion within the Roman Empire. Over the course of the 4th century, the church built significant footholds, particularly around Barcelona, Córdoba, Seville, and Toledo.