Haiti, for much of its history and including present-day has been prevailingly a Christian country, primarily Roman Catholic, although in some instances it is profoundly modified and influenced through syncretism. A common syncretic religion is Vodou, which combined the West African religions of the African slaves with Catholicism and some Native American strands; it shows similarities to Cuban Santería.
The largest Christian denomination in the country is Roman Catholicism, which is estimated to be about 55 percent of the population according to the 2018 CIA World Factbook, and 57 percent according to the Pew Research Center. The historical background is very much due to the French influence brought about through the newly conquered territories.
Protestantism has grown in recent years and Protestants are currently estimated by the CIA World Factbook to form 28.5% of the population, while the Pew Research Center estimates their share to be nearly 30 percent.
The predominant denomination is Roman Catholicism. Similar to the rest of Latin America, Haiti was colonized by Roman Catholic European powers such as the Spanish and the French. Following in this legacy, Catholicism was in the Haitian constitution as its official state religion until 1987. According to recent estimates by the CIA World Factbook and Pew Research Center, between 55 and 60% of Haitians are Catholics. Pope John Paul II visited Haiti in 1983. In a speech in the capital of Port-au-Prince, he criticized the government of Jean-Claude Duvalier. It is believed that the impact of this speech on the Catholic bureaucracy in Haiti contributed to his removal in 1986.
According to the Catholic Church in Haiti, the 10 dioceses of the two ecclesiastical provinces of Haiti include 251 parishes and about 1,500 Christian rural communities. The local clergy has 400 diocesan priests and 300 seminarians. There are also 1,300 religious missionary priests belonging to more than 70 religious order and fraternities. Vocations to the priesthood are plentiful.
The CIA Factbook reports that around 28.5% of the population is Protestant (Baptist 15.4%, Pentecostal 7.9%, Adventist 3%, Methodist 1.5% other 0.7%). Other sources put the Protestant population higher than this, suggesting that it may form one-third of the population today, as Protestant churches have experienced significant growth in recent decades. Other sources put the Protestant population higher than this, suggesting that it might have formed form one-third of the population in 2001.
The Episcopal Diocese of Haiti is the Anglican Communion diocese consisting of the entire territory of Haiti. It is part of Province 2 of the Episcopal Church (United States). Its cathedral, Holy Trinity (French: Cathédrale Sainte Trinité) located in the corner of Avenue Mgr. Guilloux and Rue Pavée in downtown Port-au-Prince, has been destroyed six times, including in the 2010 Haiti earthquake. It is the largest diocese in the Episcopal Church (United States), with 83,698 members reported in 2008.
Missionary work in Haiti by The Church of Jesus Christ of Latter-day Saints began in May 1980 and the land was dedicated for the preaching of the gospel by Thomas S. Monson, then a member of the church's Quorum of the Twelve Apostles, on 17 April 1983. As of 2017, the church reports having 46 congregations and more than 22,300 members in Haiti. In September 2012, the third and fourth Haitian stakes were created. All four stakes are based in the capital region; districts are based in Les Cayes, Saint-Marc, and Gonaïves.
At the church's April 2009 General Conference, Fouchard Pierre-Nau, a native of Jérémie, was called as an area seventy in the church's Fourth Quorum of the Seventy, the most prominent church position ever held by a Haitian. In April 2016, Pierre-Nau was released and Hubermann Bien-Aimé, a native of Gonaïves, was called to that same quorum.
The New World Afro-diasporic religion of Vodou is also practised. Vodou encompasses several different traditions, and consists of a mix encompassing African, European and indigenous Taíno religious elements. In this way, it is very similar to other Latin American syncretist movements, such as the Cuban Santería. It is more widespread in rural parts of the country, partly due to negative stigmas attached to its practice. During the season of Lent, Vodou societies create parading musical bands for a festival called Rara, and fulfill religious obligations in local spaces such as streams, rivers, trees.
The CIA World Factbook reports that 2.1% of the population identifies its religion as Vodou, but adds that "many Haitians practice elements of Vodou in addition to another religion, most often Roman Catholicism."  The proportion of Haitians that practice Vodou is disputed, due to the often syncretic manner in which it is practiced alongside Catholicism. Haitian Protestants are less likely to practice Vodou, as their churches strongly denounce it as diabolical.
There is a small Muslim community in Haiti, mainly residing in Port-au-Prince, Cap-Haïtien and its surrounding suburbs. The history of Islam on the island of Hispaniola (which Haiti shares with the Dominican Republic) begins with slavery in Haiti. Many Muslims were imported as slaves to Haiti.
The Bahá'í Faith in Haiti begins with a mention by `Abdu'l-Bahá, then head of the religion, in 1916 as one of the island countries of the Caribbean being among the places Bahá'ís should take the religion to. The first Bahá'í to visit Haiti was Leonora Armstrong in 1927. After that others visited until Louis George Gregory visited in January 1937 and he mentions a small community of Bahá'ís operating in Haiti. The first long term pioneers, Ruth and Ellsworth Blackwell, arrived in 1940. Following their arrival the first Bahá'í Local Spiritual Assembly of Haiti was formed in 1942 in Port-au-Prince. From 1951 the Haitian Bahá'ís participated in regional organizations of the religion until 1961 when Haitian Bahá'ís elected their own National Spiritual Assembly and soon took on goals reaching out into neighboring islands. The Association of Religion Data Archives (relying mostly on the World Christian Encyclopedia) estimated some 21,000 Bahá'ís in Haiti in 2005.
Sephardic Jews arrived in Saint-Domingue during the first days of the colonial period, despite that they were banned in the official Catholic edicts. They became merchants and integrated themselves into the French Catholic society. Waves of Jews continued to immigrate to the Haiti, including a group of Ashkenazi Jews escaping Hitler's Germany in the 1940s; Haiti was one of the few countries to welcome them openly. Haitian Catholics had idiosyncratic ideas about Jews, stemming from Catholic anti-Judaism, although many Vodou practitioners imagined themselves to be the descendants of Jews and to hold esoteric Judaic knowledge.
There is a group of Judaism predominantly residing in Port-au-Prince, where the community today meets at the home of businessman billionaire Gilbert Bigio, a Haitian of Syrian descent. Bigio's father first settled in Haiti in 1925 and was active in the Jewish community. In November 1947, his father played a significant role in Haiti's support for the statehood of Israel in a vote to the United Nations. Every Rosh Hashanah and Yom Kippur, services are held at his residence. The last Jewish wedding to take place in Haiti occurred 10 years ago; Bigio's daughter, while the last bris was done for his son, more than 30 years ago. Bigio owns the only Torah in all of the country, which he provides to the community for services.