Christianity is the most widely practiced religion in the world, with some 2.4 billion followers -- one-third of the global population. The Catholic church alone has 1.09 billion followers.
The United States has the largest Christian population in the world, but not the highest rate of Christians per capita. In fact, the U.S. population, which is about 71 percent Christian, according to the U.S. State Department, doesn't even make this list, ranking in 85th place worldwide.
See which countries have the largest percentage of Christians, according to various census results, the Pew Research Center and other sources.
61 (TIE). El Salvador
We'll start with El Salvador, where the population is 81.9 percent Christian.
61 (TIE). Ukraine
Ukraine's population is 81.9 percent Christian. Most belong to a branch of the Orthodox church.
Swaziland's population is 82.7 percent Christian.
57 (TIE). Costa Rica
Eighty-three percent of the population of Costa Rica is Christian, primarily Catholic.
Here, believers carry a statue of Jesus during a procession known as Jesus Nazareno of the tapes, during Holy Week in 2017. People tie ribbons to the statue to symbolize promises they make to Jesus.
57 (TIE). Dominican Republic
Eighty-three percent of the Dominican Republic is Christian, primarily Catholic.
57 (TIE). Italy
Italy's population is 83 percent Christian More than 81 percent of the population is Catholic.
Here, Pope Francis leads a Mass at the church of San Tommaso on the outskirts of Rome in 2014.
Ireland's population is 83.8 percent Christian.
More than three-quarters of residents in the Republic of Ireland identify as Catholic, while in Northern Ireland, the 2011 census found 48 percent of the population identifies as either Protestant or brought up Protestant and 45 percent as Catholic or brought up Catholic.
This photo shows a Saint Patrick's Day celebration at Saul Church on March 17, 2017, in Downpatrick, Northern Ireland.
Portugal's population is 84.3 percent Christian, and 81 percent Catholic.
The population of Liechtenstein is 84.4 percent Christian, and nearly 76 percent Catholic.
Nicaragua's population is 84.6 percent Christian, Nearly 60 percent of the population is Catholic.
Here, the faithful take part in Ash Wednesday observances at the cathedral in Managua.
51 (TIE). Bulgaria
Eighty-five percent of Bulgaria's population is Christian. Most belong to the Eastern Orthodox Church.
51 (TIE). Philippines
Eighty-five percent of the population of the Philippines is Christian and 80 percent is Catholic.
Kenya's population is 85.1 percent Christian. Protestant denominations, including the Anglican Church of Kenya, have the largest membership.
Liberia's population is 85.5 percent Christian.
45 (TIE). Cook Islands
The population of the Cook Islands in the South Pacific is 86 percent Christian.
45 (TIE). Monaco
Monaco's population is also 86 percent Christian.
45 (TIE). Bahamas
Eighty-six percent of the population of the Bahamas is Christian.
45 (TIE). Argentina
Argentina's population is 86 percent Christian, and 71 percent Catholic.
Here, priest Juan Gabriel Arias shows a tattoo depicting Christ holding the Racing Football Club shield at the church Natividad de Maria in Buenos Aires. The priest became member of the executive committee of the Racing Club after getting permission from Cardinal Jorge Bergoglio, now Pope Francis.
42 (TIE). Zimbabwe
Eighty-seven percent of Zimbabwe's population is Christian.
42 (TIE). Peru
Peru's population is 87 percent Christian and 77 percent Catholic.
42 (TIE). Guatemala
Eighty-seven percent of the population of Guatemala is Christian; 77 percent of the population is Catholic.
Seen here, Ash Wednesday in Guatemala City on March 1, 2017.
38 (TIE). Aruba
Eighty-eight percent of Aruba's population is Christian, the vast majority Catholic.
38 (TIE). Gabon
Eighty-eight percent of Gabon's population is Christian.
Here, a choir sings hymns during a rally of the Catholic Charismatic Renewal Church in Owendo in 2014.
38 (TIE). Honduras
Eighty-eight percent of the population of Honduras is Christian.
Here, believers celebrate Palm Sunday in Tegucigalpa on April 9, 2017.
38 (TIE). Venezuela
Eighty-eight percent of Venezuela's population is Christian, and 71 percent of the population is Catholic.
36 (TIE). Georgia
The nation of Georgia's population is 88.6 percent Christian. Most belong to the Georgian Orthodox Church.
Here, a Georgian Orthodox priest baptizes a child in a church in Tbilisi during the Epiphany Day in 2014.
36 (TIE). Uganda
Uganda's population is 88.6 percent Christian.
Here, believers touch a wooden crucifix at the Catholic Basilica Church of the Uganda Martyrs in Namugongo.
34 (TIE). Dominica
Dominica's population is 88.7 percent Christian.
34 (TIE). Equatorial Guinea
The population of Equatorial Guinea is 88.7 percent Christian, primarily Catholic.
Bolivia's population is 89 percent Christian, and 76 percent Catholic.
32. Cape Verde
Cape Verde's population is 89.1 percent Christian. Nearly 79 percent of the population is Catholic.
Andorra's population is 89.5 percent Christian, mostly Catholic.
28 (TIE). Lesotho
Ninety percent of the population of Lesotho, in southern Africa, is Christian.
28 (TIE). Namibia
Namibia's population is also 90 percent Christian.
28 (TIE). Brazil
Ninety percent of Brazil's population is Christian.
Here, Pope Francis celebrates Mass at Copacabana beach in 2013.
Croatia's population is 90.1 percent Christian. More than 86 percent of the population is Catholic.
26. Republic of the Congo
The population of the Republic of the Congo is 90.7 percent Christian.
Serbia's population is 91 percent Christian, mostly Orthodox.
23 (TIE). San Marino
San Marino's population is 91.6 percent Christian. More than 90 percent of the population is Catholic.
Here, Pope Benedict XVI waves as he leaves San Marino's Basilica during a visit in 2011.
23 (TIE). Malta
Malta's population is 91.6 percent Christian, primarily Catholic.
20 (TIE). Panama
Panama's population is 92 percent Christian.
Here, a woman kisses an statue of Jesus during a Holy Thursday ceremony in Panama City.
20 (TIE). Colombia
Colombia's population is also 92 percent Christian.
Here, Pope Francis waves as he leaves San Pedro Claver church in Cartagena on September 10, 2017.
20 (TIE). Democratic Republic of the Congo
Ninety-two percent of the Democratic Republic of the Congo is Christian.
Mexico's population is 92.4 percent Christian.
Here, people light candles at the Basilica de Guadalupe in Mexico City in 2013.
Rwanda's population is 93.6 percent Christian.
Ninety-four percent of Ecuador's population is Christian.
Poland's population is 94.3 percent Christian and 86.3 percent Catholic.
Here, Pope Francis meets with Polish bishops at Wawel Cathedral in Krakow in 2016.
The population of Seychelles, an island chain in the Indian Ocean, is 94.7 percent Christian.
Moldova's population is 95.3 percent Christian. The Orthodox Church is by far the largest here.
12 (TIE). Faroe Islands
The population of the Faroe Islands, in the North Atlantic, is 95.4 percent Christian. The largest denomination is Evangelical Lutheran.
12 (TIE). Micronesia
The population of Micronesia, a federation of islands in the Pacific, is 95.4 percent Christian.
Zambia's population is 95.5 percent Christian.
9 (TIE). Paraguay
Paraguay's population is 96 percent Christian.
Here, Catholics throw money from a church tower in gratitude for favors received from the Virgin Mary.
9 (TIE). Haiti
Haiti's population is 96 percent Christian, primarily Catholic. Many Haitians practice the tradition of voodoo as well as Christianity.
Greenland's population is 96.6 percent Christian, almost entirely Protestant.
7. Papua New Guinea
Papua New Guinea's population is 97 percent Christian.
The Caribbean nation of Grenada's population is 97.3 percent Christian.
Armenia's population is 97.9 percent Christian. Almost all belong to the Armenian Apostolic Church, which was founded in the first century A.D. Armenia became the first nation to declare Christianity as its state religion in 301 A.D.
3 (TIE). Greece
The population in Greece is 98 percent Christian, almost all Greek Orthodox.
Here, a Greek Orthodox worshipper prays during a Good Friday service.
3 (TIE). Romania
Romania's population is 98 percent Christian, mostly Orthodox.
Here, Romanians pray during a Palm Sunday service outside of a Greco Catholic church.
2. East Timor
The Democratic Republic of Timor-Leste (East Timor), in Southeast Asia, is 99.1 percent Christian. Nearly 97 percent of the population is Catholic.
1. Vatican City
The population of Vatican City -- home of the pope, St. Peter's Basilica, the Sistine Chapel and the Vatican Museums -- is 100 percent Catholic. Vatican City, an independent city-state of just over 100 acres located within Rome, has a population of about 1,000 people.