Brazil has the world's largest Catholic population - Catholicism is the dominant religion in the country.

An excerpt from the article 31 facts about Brazil

The Brazilian Catholic Church is the largest national community of believers in the world. Catholics there currently make up about 63% of the population, but the number of regular practitioners is estimated at 19-25%.

Recently, there has been an outflow of the faithful to communities mainly from the US, such as Jehovah's Witnesses, Mormons (about 1 million) Adventists, and various evangelical churches (such as Pentecostals).