In the Czech Republic, 47.8% of the population is irreligious (atheist, agnostic or other irreligious life stances), while 21.3% of the population are believers. The religious identity of the country has changed drastically since the first half of the 20th century, when more than 90% of Czechs were Christians. As of 2021, 11.7% of the population identified with Christianity (9.3% identifying with Catholicism and 2.4% with all other Christian denominations); 10.8% identified with other religious identities or beliefs. According to sociologist Jan Spousta, not all the irreligious people are atheists; indeed, since the late 20th century there has been an increasing distancing from both Christian dogmatism and atheism, and at the same time ideas and non-institutional models similar to those of Eastern religions have become widespread through movements started by various gurus, and hermetic and mystical paths.

The Christianisation of the Czechs (Bohemians, Moravians and Silesians) occurred in the 9th and 10th centuries, when they were incorporated into the Catholic Church and abandoned indigenous Slavic paganism. After the Bohemian Reformation which began in the late 14th century, most Czechs became Hussites, that is to say followers of Jan Hus, Petr Chelčický and other regional Proto-Protestant religious reformers. Taborites and Utraquists were the two major Hussite factions. During the Hussite Wars in the early 15th century, the Utraquists sided with the Catholic Church, and following the joint Utraquist—Catholic victory, Utraquism was accepted by the Catholic Church as a legitimate doctrine to be practised in the Kingdom of Bohemia, while all the other Hussite movements were prohibited. Jewish minorities were also present in the country.

After the Protestant Reformation in the 16th century, some in Bohemia, especially Sudeten Germans, went with the teachings of Martin Luther (Lutheranism). In the wake of the Reformation, Utraquist Hussites took a renewed increasingly anti-Catholic stance while some of the defeated Hussite factions (notably the Taborites) were revived. The defeat of Bohemian estates by the Habsburg monarchy in the Battle of White Mountain in 1620 affected the religious sentiments of the Czechs, as the Habsburgs endorsed a Counter-Reformation to forcibly reconvert all Czechs, even Utraquist Hussites, back to the Catholic Church.

Since the Battle of White Mountain, widespread anti-Catholic sentiment and resistance to the Catholic Church underlay the history of the Czech lands even when the whole population nominally belonged to the Catholic Church, and the Czechs have been historically characterised as "tolerant and even indifferent towards religion". At the end of the 18th century, Protestant and Jewish minorities were once again granted some rights, but they had to wait another century to have full equality. In 1918 the Habsburg monarchy collapsed, and in the newly independent Czechoslovakia, in 1920, the Catholic Church suffered a schism as the Czechoslovak Hussite Church re-established itself as an independent organism. In 1939–1945, Nazism annihilated or expelled most of the Jewish population. The Catholic Church lost about half of its adherents during the Marxist-Leninist period of the Czechoslovak Socialist Republic (1960–1990), and has continued to decline in the contemporary epoch after the Velvet Revolution of 1989 restored liberal democracy in Czechoslovakia. Protestantism did not recover immediately after the Habsburg Counter-Reformation; it regained some ground when the Habsburg monarchy disintegrated in the early 20th century (in 1950 about 17% of the Czechs were Protestants, mostly Hussites), although after the 1950s it declined again and today it is a very small minority (around 1%).

According to the official censuses conducted by the Czech Statistical Office, Catholicism was the religion of 39.1% of the Czechs in 1991 and has declined to 9.3% in 2021; Protestantism and other types of Christianity declined in the same period from around 5% to around 2%; at the same time, adherents of other religions or believers without an identifiable religion grew from 0.3% to 10.8%. Small minority religions in the Czech Republic include Buddhism, Islam, Paganism, Hinduism, Judaism, and others. In the census of 2021, 47.8% of Czechs declared that they did not believe in any religion, while 30.1% did not respond.

Demographics

Census statistics, 1921–2021 + Religious affiliations in the Czech Republic, census 1921–2021Religion1921193019501991200120112021Number%Number%Number%Number%Number%Number%Number% Christianity 9,150,872 91.5 9,691,392 90.8 8,332,458 93.7 4,518,512 43.9 3,094,227 30.2 1,379,802 13.2 1,241,214 11.7 —Catholicism 8,210,771 82.1 8,390,228 78.6 6,824,908 76.7 4,028,415 39.1 2,748,455 26.9 1,092,346 10.5 985,318 9.3 ——Roman Catholic Church 8,201,464 82.0 8,378,079 78.5 6,792,046 76.3 4,021,385 39.0 2,740,780 26.8 1,082,463 10.4 741,175 7.0 ——Catholics without church – – – – – – – – – – – – 235,834 2.2 ——Ruthenian Greek Catholic Church 9,307 0.1 12,149 0.1 32,862 0.4 7,030 0.1 7,675 0.1 9,883 0.1 8,309 0.1 —Eastern Orthodox Church (majority Czech and Slovak) 9,221 0.1 24,488 0.2 50,365 0.6 19,354 0.2 22,968 0.2 26,370 0.2 41,178 0.4 —Evangelical Church of Czech Brethren 231,199 2.3 290,994 2.7 401,729 4.5 203,996 2.0 117,212 1.1 51,858 0.5 32,577 0.3 —Czechoslovak Hussite Church 523,232 5.2 779,672 7.3 946,813 10.6 178,036 1.7 99,103 1.0 39,229 0.4 23,610 0.2 —Jehovah's Witnesses – – – – – – 14,575 0.1 23,162 0.2 13,069 0.1 13,298 0.1 —Augsburg Confession Lutheran churches (majority Silesian) 150,687 1.5 52,485 0.5 80,144 0.9 37,281 0.4 34,317 0.3 17,379 0.2 11,047 0.1 —German Evangelical Church in Bohemia, Moravia and Silesia – – 130,981 1.2 6,401 0.1 – – – – – – – – —Old Catholic Church of the Czech Republic 20,103 0.2 22,544 0.2 – – 2,725 0.03 1,605 0.02 1,730 0.02 672 0.01 —Other Christians 14,966 0.1 31,033 0.3 22,098 0.2 34,130 0.3 47,405 0.5 137,821 1.3 133,514 1.3 Jediism – – – – – – – – – – 15,070 0.1 21,539 0.2 Buddhism – – – – – – – – 6,817 0.07 6,101 0.06 5,757 0.05 Islam – – – – – – 495 0.0 3,699 0.04 3,358 0.03 5,244 0.05 Paganism – – – – – – – – – – 863 0.01 2,953 0.03 Pastafarianism – – – – – – – – – – – – 2,696 0.03 Hinduism – – – – – – – – 1,061 0.01 2,408 0.02 2,024 0.02 Judaism 125,083 1.3 117,551 1.1 8,038 0.1 1,292 0.01 1,515 0.01 1,474 0.01 1,901 0.02 Biotronics – – – – – – – – – – – – 1,053 0.01 Other religion 2,393 0.02 266 0.002 12,786 0.1 35,651 0.3 180,769 1.8 628 0.01 89,254 0.8 Believers without religion – – – – – – – – – – 760,316 7.3 1,005,788 9.6 No religion 716,515 7.2 834,144 7.8 519,962 5.8 4,112,864 39.9 6,039,991 59.0 3,604,095 34.5 5,027,794 47.8 Not stated 10,871 0.1 31,033 0.3 22,889 0.3 1,665,617 16.2 901,981 8.8 4,662,455 44.7 3,162,540 30.1 Total population 10,005,734 10,674,386 8,896,133 10,302,215 10,230,060 10,436,560 10,524,167

Line chart of trends, 1921–2021 Census statistics 1921–2021:

Irreligious people

In the 2021 census, 5,027,794 Czechs, corresponding to 47.8% of the total population of the Czech Republic, identified themselves as irreligious, including atheism, agnosticism and other irreligious life stances. Some Czech atheists have organised themselves in the Civic Association of Atheists (), which is a member of the Atheist Alliance International. Not all irreligious Czechs are atheists; a number of non-religious people believe or practise unorganised forms of spirituality which do not require strict adherence or identification, similar to Eastern religions.

Religions

Christianity

The Czechs gradually converted to Christianity from Slavic paganism between the 9th and the 10th centuries, and Christianity—especially the Catholic Church, with significant minorities of Protestantism, and even majorities in some periods, from the 15th century onwards—remained the religion of nearly all the population until the end of the 19th century. Bořivoj I, Duke of Bohemia, baptised by the Saints Cyril and Methodius, was the first ruler of Bohemia to adopt Christianity as the state religion. Since the late 19th century, and especially throughout the 20th century, Christianity was gradually abandoned by the majority of the Czechs and today it remains the religion of a minority. From 1950 to 2021, the official censuses of the Czech Statistical Office recorded a decline of professed Christianity from about 94% to about 12% of the population of the Czech lands.

The Marxist–Leninist period of the Czechoslovak Socialist Republic (1960–1990) certainly saw an oppression of Christianity, thus contributing to its decline, but also hampered the appearance of any alternatives in the area of religion, so that Christianity continued to have a monopolistic position in the religious interpretation of the world. Only the restoration of liberal democracy after the Velvet Revolution of 1989 opened the country to the spread of non-Christian religions. According to the scholar Jan Spousta, throughout the 20th century Christianity gradually lost its character as the Czechs' traditional religion, and was abandoned by most while turning into a religion of sincere choice for the minority who continues to identify itself with it and practise it. Spousta also found that Christians in the early 21st century tended to be older and less educated than the general population, and females were far more likely than males to be believers. Christianity remained relatively higher in percentage among the populations of the agrarian south-eastern regions of Moravia, while the percentages were already very low in the large cities and the north-western more industrialised regions of Bohemia.

Catholicism

Catholicism was the main tradition of Christianity historically practised by the Czechs after they converted from Slavic paganism, and although in the 15th and 16th century many Czechs—in many areas and periods most—joined Proto-Protestant and Protestant churches, the Habsburg monarchy which gained imperial power on the Czech lands in the early 17th century enacted a Counter-Reformation movement which reconverted most Czechs to the Catholic Church. By the time of the collapse of the Habsburg power and the establishment of independent Czechoslovakia in 1918, the position of the Catholic Church had already been weakened by criticism from the intellectual class and by the social changes brought by the rapid industrialisation of especially the northern and western parts of the country, Bohemia. At the same time, the association of Catholicism with the unpopular erstwhile Habsburg power led to widespread anticlericalism and anti-Catholicism, and to a revival of the native historical form of Czech Protestantism, namely Hussitism; in 1920, Hussites split out of the Catholic Church with about 10% of the formerly Catholic clergy and established themselves as the Czechoslovak Hussite Church.

From 1950 onwards, Marxist–Leninists gained power in Czechoslovakia, which from 1960 to 1989 became the Czechoslovak Socialist Republic, and while they fought all religions, Catholicism was targeted with particular aggressiveness. After the Velvet Revolution in 1989 and the restoration of liberal democracy in the Czech lands, Catholicism, like other forms of Christianity, did not recover and continued to lose adherents. The data from the national censuses show that Catholics decreased from 76.7% of the Czechs in 1950 prior to the Marxist-Leninist period, to 39.1% in 1991 after the fall of Marxism-Leninism, to 26.9% in 2001, to 10.5% in 2011, and to 9.3% in 2021.

Protestantism