The Catholic branch of Christianity is the most widely professed religion in Spain, with high levels of secularization . 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. 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. Only 1% of Spaniards are Protestant and most Protestants have an immigrant background.
The patron saint of Spain is St. James the Greater.