Austria identifies as 55.2% Roman Catholic according to 2021 census data, down from 73.6% in 2001 and 87.6% in 1971. The Austrian Catholic Church reported 4,609,878 registered members in 2022 across nine dioceses: Vienna, Salzburg, Linz, Graz-Seckau, Innsbruck, Feldkirch, Gurk-Klagenfurt, Eisenstadt, and Sankt Pölten. Weekly Mass attendance stands at 9.8% of registered Catholics as of 2019, a decline from 15.4% in 2005. Church tax (Kirchenbeitrag) applies to registered members at approximately 1.1% of gross income, collected by the church rather than the state. Formal church membership termination (Kirchenaustritt) is declared at civil registry offices, a process formalized in the 1868 Interkonfessionsgesetz. Between 2001 and 2021, the Catholic Church lost 1.1 million registered members through a combination of deaths, formal resignations, and non-registration of births.
The Lutheran and Reformed churches united as the Evangelical Church of the Augsburg and Helvetic Confessions in Austria (Evangelische Kirche A.B. und H.B. in Österreich) hold legal status under the 1961 Protestant Law. Protestant membership reached 271,914 in 2021, representing 3.0% of the population, concentrated in Carinthia where 12% identify as Lutheran due to 16th-century Reformation movements that persisted despite Counter-Reformation measures. The Evangelical community maintains 229 parishes and 286 pastors as of 2022. Islamic communities numbered 745,600 adherents in 2021, constituting 8.3% of the population, primarily Sunni Muslims of Turkish and Bosnian origin. The Islamic Religious Authority (Islamische Glaubensgemeinschaft in Österreich) received official recognition in 1912 under Franz Joseph I, making Austria the first Western European country to legally recognize Islam. The 2015 Islam Law (Islamgesetz) regulates foreign funding of mosques and requires imams to possess German language certification.
Orthodox Christians totaled 530,000 in 2021, or 5.9% of the population. The Serbian Orthodox Eparchy of Austria-Switzerland counts approximately 300,000 faithful, while the Romanian Orthodox Metropolis of Austria has 95,000 registered members. The Russian Orthodox Diocese of Vienna and Austria operates 12 parishes. Byzantine Rite Catholics number approximately 28,000, predominantly Ukrainian and Romanian Greek Catholics. Judaism claims 15,000 to 20,000 adherents according to 2021 estimates, concentrated in Vienna where the Jewish community maintains 25 synagogues. The Israelitische Kultusgemeinde Wien serves as the central organization, established in 1852. Before the Anschluss in 1938, Austria's Jewish population numbered 206,000, with 185,000 in Vienna alone. The Holocaust reduced this to 4,500 survivors by 1945.
No religious affiliation was declared by 22.4% of respondents in the 2021 census, up from 12% in 2001. This category includes atheists, agnostics, and persons who declined to state religious preference. The Austrian Freethinkers Association (Freidenker-Verband Österreichs) was founded in 1887 and maintains approximately 1,500 members. Religious instruction remains mandatory in public schools as established in Article 17 of the 1867 Basic Law on the General Rights of Citizens, though students may opt out with parental consent. The subject Ethik (ethics) became an alternative for non-participating students in 2021 after a two-decade pilot program.
Religious holidays shape the Austrian calendar through 13 federal public holidays, of which eight derive from Christian observances: January 1 (Circumcision of Christ, now secularized as New Year), Easter Monday, Ascension Day (39 days after Easter Sunday), Whit Monday (50 days after Easter), Corpus Christi (60 days after Easter), August 15 (Assumption of Mary), November 1 (All Saints), December 8 (Immaculate Conception), and December 25-26 (Christmas). May 1 (Labor Day) and October 26 (National Holiday commemorating the 1955 neutrality declaration) serve secular functions. Good Friday became a general public holiday in 2019 after the European Court of Justice ruled Austria's previous practice of granting the day only to Protestants discriminatory.
Sunday remains protected as a day of rest under the 1983 Rest Period Act (Arbeitsruhegesetz), which prohibits most commercial activities. Bakeries may open Sunday mornings until 11:00, and shops at train stations, airports, and tourist zones receive exemptions. Large supermarket chains remain closed. Vienna liberalized Sunday shopping in six designated shopping Sundays per year, typically before Christmas and during seasonal sales. The Austrian Trade Union Federation (Österreichischer Gewerkschaftsbund) opposes expanded Sunday commerce, citing worker protection rather than religious observance.
Church bells regulate village life in rural areas, particularly in Tyrol, Salzburg, and Vorarlberg where 78% of municipalities have populations under 5,000. Bells ring the Angelus at 06:00, 12:00, and 18:00 daily in Catholic parishes. Death knells (Sterbeglocken) announce funerals. Wedding bells ring in specific patterns. The Constitutional Court ruled in 1973 that bell-ringing constitutes protected religious expression, though municipalities may restrict nighttime ringing between 22:00 and 06:00. Electronic bells have replaced swinging bells in some urban parishes to reduce noise.
Religious processions mark the calendar in alpine regions. The Corpus Christi procession (Fronleichnamsprozession) on the Thursday 60 days after Easter involves 1,200 documented processions nationwide, including the Traunsee boat procession where 30 to 40 decorated vessels carry the Eucharist across the lake. The Hallstatt procession has occurred since 1623. Georgiritt (St. George's Ride) on April 23 in Bad Mitterndorf involves 300 horses and riders blessing the coming agricultural season. Leonhardifahrt (St. Leonard's procession) in Bad Tölz and Tamsweg in November blesses livestock with horse-drawn wagons carrying relics. The Samson processions in Lungau and Mühlviertel feature 3.5-meter-tall Biblical giant figures paraded through villages during summer months.
Pilgrimage to Mariazell Basilica in Styria draws 250,000 visitors annually, making it Central Europe's most visited Marian shrine. The wooden Madonna statue dates to approximately 1157. Pope John Paul II celebrated Mass there September 13, 1983 before 70,000 pilgrims. Walking pilgrimages (Fußwallfahrten) from Vienna cover 135 kilometers over three days. The Styrian state pilgrimage occurs the Saturday before September 8 each year. The St. Peter's Abbey Church in Salzburg traces continuous monastic presence to 696, though some scholarship places the foundation between 790 and 800. The abbey archives contain the Annales Iuvavenses (Salzburg Annals) documenting events from 700 to 1200.
Religious education (Religionsunterricht) occurs two hours weekly in Austrian schools, separated by denomination. Catholic instruction follows curriculum approved by the Austrian Bishops' Conference. Islamic instruction began in 1982 with 1,689 students and expanded to 73,000 students by 2022 taught by 530 instructors. Orthodox instruction serves 21,000 students across multiple rites. Private confessional schools operate under the 1962 Private Schools Act (Privatschulgesetz), with the state covering teacher salaries for approved institutions. As of 2022, 223 Catholic schools enrolled 97,000 students, representing 11% of compulsory education enrollment.