Religion in Ireland: History and Statistics

Houses and catherdral in Cobh, Ireland
Cobh is a harbour town in County Cork, Ireland. In the background is the Cobh Cathedral against a dramatic skyline. benstevens / Getty Images

Roman Catholicism is the dominant religion in Ireland, and it has played a significant political and social role in the community since the 12th century, though the Constitution guarantees the right of religious freedom. Of the 5.1 million people in the Republic of Ireland, a majority of the population—about 78%—identifies as Catholic, 3% are Protestant, 1% Muslim, 1% Orthodox Christian, 2% unspecified Christian, and 2% are members of other faiths. Notably, 10% of the population identify themselves as nonreligious, a number that has continued to increase. 

Key Takeaways

  • Though the constitution guarantees the freedom of religion, Roman Catholicism is the dominant religion in Ireland.  
  • Other main religions in Ireland include Protestantism, Islam, Orthodox, and nondenominational Christian, Judaism, and Hinduism. 
  • Approximately 10% of Ireland is nonreligious, a number that has risen in the past 40 years. 
  • As immigration from the Middle East, Africa, and Southeast Asia increases, the populations of Muslims, Christians, and Hindus continue to grow.

Though reverence for the Catholic Church was explicitly removed from the Constitution in the 1970s, the document retains religious references. However, progressive political changes, including the legalization of divorce, abortion, and gay marriage, have mirrored the decline in practicing Catholics.

History of Religion in Ireland

According to Irish folklore, the first Celtic deities, the Tuatha Dé Dannan, descended into Ireland during a thick fog. The deities are thought to have left the island when the ancient ancestors of the Irish arrived. During the 11th century, Catholic monks recorded these Irish mythological stories, altering the oral histories to reflect Roman Catholic teachings.

Over time, Catholicism adopted ancient Irish mythology into clerical teachings, and Ireland became one of the most fiercely Catholic countries in the world. The first diocese was established in the 12th century, though Catholicism was made illegal by Henry VIII during the conquest of Ireland. Those loyal to the Church continued to practice underground until the Catholic Emancipation of 1829.

Ireland won independence from the United Kingdom in 1922. Though the 1937 constitution guaranteed the right of religious freedom, it formally recognized Christian churches and Judaism within the country and granted the Catholic Church a “special position.” These formal recognitions were removed from the Constitution in the 1970s, though it still retains several religious references.

In the past 40 years, Catholicism has seen a dramatic decline, particularly in the younger generations, as a result of Church scandals and progressive socio-political movements. Additionally, as immigration to Ireland increases, populations of Muslims, Hindus, and non-Catholic Christians continues to grow.

Roman Catholicism 

Most of the population of Ireland, about 78%, is affiliated with the Catholic Church, though this number has declined significantly since the 1960s, when the population of Catholics was close to 98%.

The past two generations have seen a rise in cultural Catholicism. Cultural Catholics are raised in the Church and often attend mass for special occasions, such as Christmas, Easter, baptisms, weddings, and funerals, though they are not practicing members of the community. They do not attend mass regularly or commit time to devotionals, and they do not follow the teachings of the Church.

Pope Francis Holds The Closing Mass Of His Ireland Visit
Pope Francis arrives for the Closing Mass in Phoenix Park on August 26, 2018 in Dublin, Ireland. A congregation of approximately 500,000 people gathered for the event. Matt Cardy / Getty Images

Practicing Catholics in Ireland tend to be members of the older generations. This decrease in devout Catholicism is in line with the progressivism of the country’s politics over the past 30 years. In 1995, the ban on divorce was removed from the Constitution, and a 2018 referendum overturned the constitutional ban on abortion. In 2015, Ireland became the first country to legalize gay marriage by popular referendum.

Roman Catholicism has faced scrutiny in recent years over child abuse by members of the clergy, and Ireland is no exception to this. In Ireland, these scandals have included mental, emotional, physical, and sexual abuse of children, the fathering of children by priests, and major cover-ups by members of the clergy and of government.


Protestantism is the second largest religion in Ireland and third most significant religious grouping, behind Catholicism and those who identify as nonreligious. Though Protestants were present in Ireland prior to the 16th century, their numbers were insignificant until Henry VIII established himself as the king and head of the Church of Ireland, banning Catholicism and dissolving the country’s monasteries. Elizabeth I subsequently removed Catholic farmers from ancestral lands, replacing them with Protestants from Great Britain.

After Irish independence, many Protestants fled Ireland for the United Kingdom, though the Church of Ireland was recognized by the 1937 Constitution. The population of Irish Protestants, specifically Anglicans (Church of Ireland), Methodists, and Presbyterians.

Queen Elizabeth I - portrait
Queen Elizabeth I - portrait from an engraving by Crispin de Passe, 1592 - Queen of England and Ireland. Culture Club / Getty Images

Protestantism in Ireland is focused heavily on self-reliance and responsibility for oneself. Members of Protestant denominations are able to communicate directly with God without first interacting with a spiritual leader, placing the responsibility of spiritual learning on the individual.

Though most Irish Protestants are members of the Church of Ireland, there is a rising population of African Methodist immigrants. Though the animosity between Catholics and Protestants in Ireland has declined over the centuries, many Irish Protestants report feeling less Irish as a result of their religious identities. 


Though Muslims are documented to have been present in Ireland for centuries, the first Islamic community was not formally established until 1959. Since then, numbers of Muslims in Ireland has continued to rise steadily, particularly during the Irish economic boom of the 1990s that brought in immigrants and asylum seekers from Africa and the Middle East.

Irish Muslims tend to be younger than Protestants and Catholics, with a median age of 26. Most Muslims in Ireland are Sunni, though there are communities of Shias as well. In 1992, Moosajee Bhamjee became the first Muslim member of the Irish parliament, and in 2018, Irish singer Sinead O’Connor publically converted to Islam.

Other Religions in Ireland

Minority religions in Ireland include Orthodox and non denominational Christians, Pentecostals, Hindus, Buddhists, and Jews.

Though only in small numbers, Judaism has been present in Ireland for centuries. Jews received formal recognition as a protected religious group in the 1937 Constitution, a progressive move during the tumultuous political climate just before World War II.

Hindus and Buddhists immigrated to Ireland in search of economic opportunity and to escape persecution. Buddhism among Irish nationals is surging in popularity, as the first Irish Buddhist Union was established in 2018.

Note: This article is written about the Republic of Ireland, not including Northern Ireland, a region of the United Kingdom


  • Bartlett, Thomas. Ireland: a History. Cambridge University Press, 2011.
  • Bradley, Ian C. Celtic Christianity: Making Myths and Chasing Dreams. Edinburgh U.P, 2003.
  • Bureau of Democracy, Human Rights, and Labor. 2018 Report on International Religious Freedom: Ireland. Washington, DC: U.S. Department of State, 2019.
  • Central Intelligence Agency. The World Factbook: Ireland. Washington, DC: Central Intelligence
  • Agency, 2019.
  • Joyce, P. W. A Social History of Ancient Ireland. Longmans, 1920.
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Perkins, McKenzie. "Religion in Ireland: History and Statistics." Learn Religions, Oct. 13, 2021, Perkins, McKenzie. (2021, October 13). Religion in Ireland: History and Statistics. Retrieved from Perkins, McKenzie. "Religion in Ireland: History and Statistics." Learn Religions. (accessed June 5, 2023).