Religion in Spain

The Catholic branch of Christianity is the most widely professed religion in Spain, with high levels of secularization as of 2022. Freedom of religion is guaranteed by the Spanish Constitution.

The Pew Research Center ranked Spain as the 16th out of 34 European countries in levels of religiosity, with 21% of the population declaring they were "highly religious" in the poll. 3% of Spaniards consider religion as one of their three most important values, lower than the 5% European average.

Judaism and Christianity were introduced in the Iberian Peninsula in Roman times, with the latter absorbing many elements from "pagan" practices that survived for a while even among Christianized populations. Islam was introduced in the Iberian Peninsula after the Muslim conquest in the 8th century, which resulted in the establishment of Al-Andalus. In the late 15th to early 16th century, Jews and Muslims were forced to choose between conversion or expulsion, with the fostering of Catholic uniformity across the territory remaining a major concern for both State and Church authorities throughout the two following centuries. Connected to the Old Regime, the Catholic Church became the most controversial institution in Spain in the 19th and 20th centuries, struggling to find ways to relate to the nascent liberal society as well as clashing with governments seeking to find an acceptable delimitation of the role of religion in public affairs. Since the end of the Francoist dictatorship practical secularization has grown strongly. The 1978 Constitution abolished Catholicism as the official religion of the state, while recognizing "the religious beliefs of all Spaniards" and establishing "appropriate cooperation" with the Catholic Church and other confessions.

According to the Spanish Center for Sociological Research, 52.0% of Spanish citizens self-identify as Catholics, (35.2% define themselves as non-practising, while 16.8% as practising), 2.4% as followers of other faiths (including Islam, Protestant Christianity, Buddhism etc.), and 44.1% identify as: atheists (16.8%), agnostics (14.4%) or non-believers (12.9%), as of September 2023.

Most Spaniards do not participate regularly in weekly religious worship. A July 2021 study shows that of the Spaniards who identify themselves as religious, 36% never attend mass, 20.8% barely ever attend mass, 19% attend mass a few times a year, 6.8% two or three times per month, 13.4% every Sunday and holidays, and 2.9% multiple times per week. According to a 2021 survey, those who go to church several times a year are 17.3% of the total population; those who go several times a month, 9.3%; those who go every Sunday and all holy days of obligation, 14.9%; and those who go several times a week, 4.3%.

Although a majority of Spaniards self-identify as Catholics, younger generations tend to ignore the Church's moral doctrines on issues such as pre-marital sex, homosexuality, same-sex marriage or contraception. The total number of parish priests shrank from 24,300 in 1975 to 18,500 in 2018, with an average age of 65.5 years. By contrast, many expressions of popular religiosity still thrive, often linked to local festivals. Several instances of Catholic cultural practices are present among the general population, such as Catholic baptisms and funerals, Holy Week processions, pilgrimages (such as the Way of St. James), patron saints and many festivals.

A Survey published in 2019 by the Pew Research Center found that 54% of Spaniards had a favorable view of Muslims, while 76% had a favorable view of Jews. Spain has been regarded as generally unwelcoming of Protestantism, with only 1% of Spaniards being Protestant and most Protestants being of an immigrant background.

The patron saint of Spain is St. James the Greater.