France does not conduct a modern population census based on religious affiliation. A question about religion was included in the national census until 1872, when it was removed, although it continued to be used in Alsace under the Concordat system until 1962. Religious affiliation can nevertheless be measured through statistical surveys conducted under appropriate legal safeguards.
As of 2026, two major studies provide a detailed picture of France’s religious landscape: the Trajectories and Origins 2 survey, conducted by the French national statistics institute (Insee) and the National Institute for Demographic Studies (Ined) in 2019–2020, and a large-scale Ifop survey carried out in 2025.
The two studies do not produce exactly the same figures because they examine different populations. The Insee-Ined survey covers people aged 18 to 59 living in metropolitan France. Based on interviews with more than 27,000 people, it found that 51% reported having no religion, 29% identified as Catholic, 10% as Muslim, and approximately 10% belonged to other religious traditions. Non-Catholic Christian denominations alone accounted for around 9% of the population surveyed.
The 2025 Ifop study, by contrast, covers people aged 15 and over living in metropolitan France. It therefore includes those aged 60 and above, among whom identification with Catholicism remains more widespread. Of the more than 14,000 people surveyed, 43% identified as Catholic, 37.5% reported having no religion, 7% as Muslim, 4% as Protestant or Evangelical Christian, 1% as Orthodox Christian, 1% as Jewish, and 1% as Buddhist. A further 2.5% identified with another religion, while 3% did not answer the question.
These differences do not mean that one survey is necessarily more accurate than the other. A figure such as “29% Catholic” or “43% Catholic” only makes sense when accompanied by a clear explanation of the population being measured. People aged 60 and over are excluded from the Insee-Ined survey but included in the Ifop study. The wording of questions, the religious categories offered to respondents, and the date of each survey can also influence the results.
One trend, however, is unmistakable: the growing proportion of people who do not identify with any religion. To make a precise comparison between its two surveys, Insee and Ined examined the common age group of 18 to 49. Between 2008–2009 and 2019–2020, the proportion of people reporting no religious affiliation rose from 45% to 53%. Over the same period, the proportion identifying as Catholic fell from 43% to 25%.
Ifop observed a similar transformation over a much longer period. According to its historical polling series, the proportion of people identifying as Catholic declined from 83% in 1985 to 43% in 2025, while the share of those reporting no religion increased from 13% to approximately 37%. These figures do not constitute a census, and survey methods have evolved over time, but the scale of the decline in Catholic identification is unmistakable.
Catholicism nevertheless remains France’s largest declared religion. This does not mean that most people who identify as Catholic regularly practice their faith. The Insee-Ined survey found that only 8% of Catholics regularly attend a place of worship. Catholic identity can therefore encompass both active religious commitment and a much more distant attachment rooted primarily in family tradition or cultural heritage.
Islam is the second-largest declared religion in France. It accounts for 10% of people aged 18 to 59 in the 2019–2020 Insee-Ined survey and approximately 7% of those aged 15 and over in the 2025 Ifop study. Here again, much of the difference reflects the age structure of the populations surveyed. Ifop’s historical series shows a steady increase in Muslim identification: 4% in 2009, 5.5% in 2016, and 7% in 2025.
France’s Christian landscape extends well beyond Catholicism. Protestantism includes the historic Lutheran and Reformed Churches, alongside a wide range of Evangelical and Pentecostal denominations. Ifop estimates that Protestants and Evangelical Christians together account for approximately 4% of the population aged 15 and over. The Insee-Ined survey, meanwhile, shows an increase in the proportion of people identifying with a Christian religion other than Catholicism, reaching 9% of those aged 18 to 59 in 2019–2020.
Orthodox Christianity represents approximately 1% of the population according to Ifop. Its presence in France has developed partly through successive waves of migration from Eastern Europe, the Caucasus, and the Middle East.
Judaism is also estimated at approximately 1% in the Ifop survey. This percentage measures declared religious affiliation, rather than everyone who may have Jewish ancestry, family history, or cultural identity. Different estimates of France’s Jewish population do not necessarily measure the same reality.
Buddhism similarly accounts for approximately 1% of the population according to Ifop. The Insee-Ined survey estimates a lower proportion among those aged 18 to 49, at around 0.5%. These figures also illustrate the limitations of absolute estimates frequently cited for the number of Buddhists in France. Results can vary substantially depending on whether researchers measure declared religious affiliation, regular practice, family background, or a personal connection with certain Buddhist practices.
Religious affiliation and religious practice are, in fact, two different realities. In the detailed Insee-Ined study, only 8% of Catholics reported regularly attending a place of worship. The figure was slightly above 20% among Muslims, non-Catholic Christians, and Buddhists, and reached 34% among Jews.
Religion also occupies a very different place in people’s sense of personal identity. Among respondents aged 18 to 49 surveyed in 2019–2020, only 6% of Catholics mentioned religion as one of the important dimensions of their identity, compared with 30% of Muslims and 54% of Jews.
The evidence available in 2026 therefore points less to the disappearance of religion in France than to a profound transformation of the country’s religious landscape. The proportion of people with no religious affiliation has increased substantially, Catholic identification has declined, Islam has become firmly established as the second-largest declared religion, and Christianity itself has grown more diverse.
At the same time, Judaism, Buddhism, Orthodox Christianity, and numerous other traditions continue to contribute to a religious landscape that is considerably more pluralistic than it was a few decades ago.
Above all, the statistics highlight an essential distinction: belonging to a religion, holding religious beliefs, practicing a religion, and considering religion an important part of one’s identity are four different things. No single statistic can adequately capture them all.