According to the French national institute for statistical and economic studies (INSEE), in 2019‑2020, 51% of the population aged 18 to 59 in metropolitan France declared that they had no religion.
On the increase over the past ten years, this religious disaffiliation concerns 58% of people without immigrant ancestry, 19% of immigrants who arrived after 16 years of age and 26% of descendants of two immigrant parents. If Catholicism remains the first religion (29% of the population declares itself Catholic), Islam is declared by a growing number of faithful (10%) and confirms its place as the second religion in France. The number of people declaring another Christian religion also increases, reaching 9%.