| Africa | West Africa | 7,200,000 | 23.0 | French | Yamoussoukro | Our Lady of Peace | Minority religion | Yes |
| Afghanistan | Asia | South Asia | 200 | 0.001 | Pashto, Dari | Kabul | None | Virtually non-existent, Islam state religion | No |
| Albania | Europe | Southeastern Europe | 420,000 | 15.0 | Albanian | Tirana | Saint Anthony of Padua, Saint Teresa of Calcutta | Significant minority, Muslim majority | No |
| Algeria | Africa | North Africa | 5,000 | 0.01 | Arabic, Berber | Algiers | [[Saint Augustine of Hippo]] | | |
| Andorra | Europe | Southern Europe | 72,000 | 88.0 | Catalan | Andorra la Vella | Our Lady of Meritxell | Majority religion, co-official with state | No |
| Angola | Africa | Southern Africa | 21,000,000 | 56.4 | Portuguese | Luanda | Our Lady of Muxima, Immaculate Heart of Mary | Majority religion, secular state | |
| Antigua and Barbuda | North America | Caribbean | 8,200 | 8.0 | English | St. John's | Our Lady of Perpetual Help | Minority religion | No |
| Argentina | South America | Latin America | 33,000,000 | 72.0 | Spanish | Buenos Aires | Our Lady of Luján, Saint Joseph | Majority religion, constitutionally secular | No |
| Australia | Australia | Australasia | 5,520,000 | 20.0 | English | Canberra | Our Lady Help of Christians | Largest religious denomination, constitutionally secular | No |
| Austria | Europe | Central Europe | 5,000,000 | 55.0 | German | Vienna | Saint Leopold III, Saint Florian | Majority religion, secular state | |
| Bahamas | North America | Caribbean | 48,000 | 12.0 | English | Nassau | Our Lady of the Immaculate Conception | Minority religion | No |
| Bahrain | Asia | Persian Gulf | 80,000 | 5.0 | Arabic | Manama | Our Lady of Arabia | Minority religion, Islam dominant | No |
| Bangladesh | Asia | South Asia | 400,000 | 0.23 | Bengali | Dhaka | Our Lady of the Holy Rosary | Minority religion, Islam dominant | No |
| Barbados | North America | Caribbean | 11,000 | 4.0 | English | Bridgetown | Our Lady of Fatima | Minority religion | No |
| Belarus | Europe | Eastern Europe | 1,400,000 | 15.0 | Belarusian, Russian | Minsk | Our Lady of Budslau | Significant minority, Orthodox majority | No |
| Belgium | Europe | Western Europe | 6,500,000 | 56.0 | Dutch, French, German | Brussels | Saint Joseph, Saint Michael | Major religion, historically dominant | No |
| Belize | North America | Central America | 164,000 | 40.0 | English | Belmopan | Our Lady of Guadalupe | Minority religion | No |
| Benin | Africa | West Africa | 3,900,000 | 30.0 | French | Porto-Novo | Our Lady of Peace | Significant minority religion, Vodoun and Islam also prominent | |
| Bhutan | Asia | South Asia | 1,000 | 0.125 | Dzongkha | Thimphu | None | Minority religion, Buddhism dominant | No |
| Bolivia | South America | Latin America | 9,500,000 | 77.0 | Spanish, Quechua, Aymara, Guarani | La Paz | Our Lady of Copacabana, Saint Francis Solano | Majority religion, constitutionally secular | No |
| Bosnia and Herzegovina | Europe | Southeastern Europe | 460,000 | 12.0 | Bosnian, Croatian, Serbian | Sarajevo | Our Lady of Međugorje | Significant minority, Muslim majority | No |
| Botswana | Africa | Southern Africa | 81,000 | 3.0 | Setswana, English | Gaborone | Our Lady of the Desert | Minority religion | Yes |
| Brazil | South America | Eastern South America | 129,600,000 | 60.0 | Portuguese | Brasília | Our Lady of Aparecida | Majority religion | No |
| Brunei | Asia | Southeast Asia | 8,000 | 1.7 | Malay | Bandar Seri Begawan | Our Lady of the Assumption | Minority religion, Islam state religion | No |
| Bulgaria | Europe | Southeastern Europe | 50,000 | 0.7 | Bulgarian | Sofia | Saint John of Rila | Minority religion, Orthodox majority | No |
| Burkina Faso | Africa | West Africa | 4,400,000 | 19.0 | French | Ouagadougou | Our Lady of Yagma | Minority religion | Yes |
| Burundi | Africa | East Africa | 7,700,000 | 60.0 | Kirundi, French, English | Gitega | Our Lady of Peace | Majority religion | Yes |
| Byzantine Empire | Europe, Asia, Africa | | 500,000 | 3.0 | Greek, Latin | Constantinople | Saint Andrew, Saint John Chrysostom | Minority religion, Orthodoxy dominant | Yes |
| Cambodia | Asia | Southeast Asia | 20,000 | 0.12 | Khmer | Phnom Penh | Our Lady of the Mekong | Minority religion, Buddhism dominant | No |
| Cameroon | Africa | Central Africa | 7,000,000 | 26.0 | English, French | Yaoundé | None officially designated | Major religion, alongside Protestantism and Islam | No |
| Canada | North America | North America | 12,600,000 | 30.0 | English, French | Ottawa | Saint Joseph, Saint Anne | Minority religion | No |
| Cape Verde | Africa | West Africa | 462,000 | 77.0 | Portuguese, Cape Verdean Creole | Praia | Our Lady of Grace | Majority religion | Yes |
| Central African Republic | Africa | Central Africa | 1,740,000 | 30.0 | French, Sango | Bangui | Our Lady of the Immaculate Conception | Significant minority religion, secular state | |
| Chad | Africa | Central Africa | 1,900,000 | 10.0 | French, Arabic | N’Djamena | Our Lady of Peace | Minority religion, secular state | |
| Chile | South America | Latin America | 11,000,000 | 56.0 | Spanish | Santiago | Our Lady of Mount Carmel, Saint James the Greater | Majority religion, constitutionally secular | No |
| China | Asia | East Asia | 12,000,000 | 0.85 | Mandarin | Beijing | Our Lady of Sheshan, Saint Joseph | Minority religion, state-regulated | No |
| Colombia | South America | Northern South America | 39,000,000 | 75.0 | Spanish | Bogotá | Virgin of Chiquinquirá, Saint Peter Claver | Majority religion | No |
| Comoros | Africa | Indian Ocean | 2,000 | 0.2 | Comorian, Arabic, French | Moroni | None | Clandestine minority religion | Yes |
| Costa Rica | North America | Central America | 3,640,000 | 70.0 | Spanish | San José | Our Lady of the Angels | Majority religion | No |
| Croatia | Europe | Southeastern Europe | 2,900,000 | 76.0 | Croatian | Zagreb | Our Lady of Marija Bistrica, Saint Joseph | Dominant religion, strong cultural role | No |
| Cuba | North America | Caribbean | 6,700,000 | 60.0 | Spanish | Havana | Our Lady of Charity of El Cobre | Majority religion under restrictions | No |
| Cyprus | Europe | Eastern Mediterranean | 38,000 | 2.9 | Greek, Turkish | Nicosia | Our Lady of Fatima | Minority religion, Greek Orthodoxy and Islam dominant | No |
| Czech Republic | Europe | Central Europe | 1,050,000 | 10.0 | Czech | Prague | Saint Wenceslaus, Saint Ludmila | Minority religion | No |
| Dahomey Kingdom | Africa | | 10,000 | 3.0 | Fon, French | Abomey | None | Minority religion, Vodoun dominant | |
| Democratic Republic of the Congo | Africa | Central Africa | 54,000,000 | 50.0 | French | Kinshasa | Our Lady of the Congo, Saint Joseph | Majority religion, secular state | |
| Denmark | Europe | Northern Europe | 48,000 | 0.8 | Danish | Copenhagen | Saint Canute | Minority religion, Lutheran majority | No |
| Djibouti | Africa | Horn of Africa | 5,000 | 0.5 | Somali, Arabic, French | Djibouti City | Our Lady of the Good Shepherd | Minority religion | Yes |
| Dominica | North America | Caribbean | 44,000 | 61.0 | English | Roseau | Our Lady of La Salette | Majority religion | No |
| Dominican Republic | North America | Caribbean | 5,200,000 | 48.0 | Spanish | Santo Domingo | Our Lady of Altagracia, Saint Dominic | Significant minority religion | No |
| East Timor | Asia | Southeast Asia | 1,300,000 | 96.0 | Tetum, Portuguese | Dili | Our Lady of Aitara | Dominant religion | No |
| Ecuador | South America | Latin America | 14,000,000 | 77.0 | Spanish, Quechua, Shuar | Quito | Sacred Heart of Jesus, Our Lady of Mercy | Majority religion, constitutionally secular | No |
| Egypt | Africa | Northeast Africa | 250,000 | 0.23 | Arabic | Cairo | Saint Mark the Evangelist | Small minority religion, Islamic state | |
| El Salvador | North America | Central America | 3,250,000 | 50.0 | Spanish | San Salvador | Our Lady of Peace, Saint Óscar Romero | Majority religion | No |
| Equatorial Guinea | Africa | Central Africa | 1,400,000 | 82.0 | Spanish, French, Portuguese | Malabo | Our Lady of Malabo | Majority religion | Yes |
| Eritrea | Africa | Horn of Africa | 148,000 | 4.0 | Tigrinya, Arabic, English | Asmara | Our Lady of the Rosary | Minority religion | Yes |
| Estonia | Europe | Northern Europe | 6,000 | 0.5 | Estonian | Tallinn | Saint Stanislaus | Minority religion, secular majority | No |
| Eswatini | Africa | Southern Africa | 60,000 | 5.0 | SiSwati, English | Mbabane | Our Lady of the Assumption | Minority religion | Yes |
| Ethiopia | Africa | Horn of Africa | 800,000 | 0.6 | Amharic (working), regional languages | Addis Ababa | Our Lady of Zion | Minority religion | Yes |
| Federated States of Micronesia | Australia | Western Pacific | 55,000 | 52.0 | English | Palikir | Our Lady of Mercy | Major religion, Protestantism also prominent | No |
| Fiji | Australia | South Pacific | 83,700 | 9.0 | English, Fijian, Fiji Hindi | Suva | Our Lady of Perpetual Help | Minority religion, Methodism and Hinduism dominant | No |
| Finland | Europe | Northern Europe | 16,000 | 0.3 | Finnish, Swedish | Helsinki | Saint Henry | Minority religion, Lutheran majority | No |
| France | Europe | Western Europe | 32,000,000 | 47.0 | French | Paris | Our Lady of the Assumption, Saint Joan of Arc, Saint Thérèse of Lisieux | Significant religion, secular state | |
| Frankish Empire | Europe | | 4,000,000 | 80.0 | Latin, Frankish | Aachen | Saint Martin of Tours | State religion under Carolingian rulers | Yes |
| Gabon | Africa | Central Africa | 1,400,000 | 59.0 | French | Libreville | Our Lady of Libreville | Majority religion | Yes |
| Georgia | Asia | South Caucasus | 19,000 | 0.5 | Georgian | Tbilisi | Saint Nino | Minority religion, Orthodox majority | No |
| Georgia | Eurasia | Caucasus | 19,000 | 0.5 | Georgian | Tbilisi | Our Lady of the Immaculate Conception | Minority religion, Georgian Orthodoxy dominant | No |
| Germany | Europe | Central Europe | 21,000,000 | 25.0 | German | Berlin | Saint Boniface, Saint Michael the Archangel | Significant minority religion, secular state | |
| Ghana | Africa | West Africa | 4,400,000 | 13.0 | English | Accra | Our Lady of the Apostles | Minority religion | Yes |
| Greece | Europe | Southern Europe | 50,000 | 0.5 | Greek | Athens | Saint Andrew, Saint Dionysius | Minority religion, Orthodoxy dominant (90%) | No |
| Greenland | North America | Arctic | 100 | 0.2 | Greenlandic, Danish | Nuuk | Saint Olaf | Small minority religion, Lutheranism dominant | No |
| Grenada | North America | Caribbean | 52,000 | 44.4 | English | St. George's | Our Lady of the Immaculate Conception | Significant minority religion | No |
| Guatemala | North America | Central America | 8,100,000 | 45.0 | Spanish | Guatemala City | Our Lady of the Rosary, Saint James the Greater | Minority religion | No |
| Guinea | Africa | West Africa | 426,000 | 3.0 | French | Conakry | Our Lady of Guinea | Minority religion | Yes |
| Guinea-Bissau | Africa | West Africa | 220,000 | 10.0 | Portuguese, Guinea-Bissau Creole | Bissau | Our Lady of Cacheu | Minority religion | Yes |
| Guyana | South America | Caribbean | 65,000 | 8.0 | English | Georgetown | Our Lady of the Assumption | Minority religion, Christianity dominant | No |
| Haiti | North America | Caribbean | 6,400,000 | 55.0 | Haitian Creole, French | Port-au-Prince | Our Lady of Perpetual Help | Majority religion | No |
| Holy Roman Empire | Europe | | 15,000,000 | 75.0 | Latin, German | Aachen | Saint Boniface | State religion under multiple emperors | Yes |
| Honduras | North America | Central America | 4,725,000 | 45.0 | Spanish | Tegucigalpa | Our Lady of Suyapa | Minority religion | No |
| Hungary | Europe | Central Europe | 3,800,000 | 39.0 | Hungarian | Budapest | Saint Stephen, Our Lady of Hungary | Largest religion, strong cultural role | No |
| Iceland | Europe | Northern Europe | 15,000 | 3.9 | Icelandic | Reykjavík | Saint Thorlak | Minority religion, Lutheranism dominant | No |
| India | Asia | South Asia | 20,000,000 | 1.38 | Hindi, English | New Delhi | Our Lady of Vailankanni, Saint Thomas the Apostle | Minority religion, Hinduism dominant | No |
| Indonesia | Asia | Southeast Asia | 8,400,000 | 3.0 | Indonesian | Jakarta | Our Lady of Perpetual Help | Minority religion, Islam dominant | No |
| Iran | Asia | Middle East | 20,000 | 0.02 | Persian | Tehran | Saint Maruthas | Small minority religion, Islamic state | No |
| Iraq | Asia | Middle East | 300,000 | 0.7 | Arabic, Kurdish | Baghdad | Saint Thomas the Apostle | Small minority religion, Islamic state | |
| Ireland | Europe | Northern Europe | 3,740,000 | 73.3 | Irish, English | Dublin | Saint Patrick, Saint Brigid, Saint Columba | Majority religion, constitutionally secular | No |
| Israel | Asia | Middle East | 180,000 | 1.9 | Hebrew, Arabic | Jerusalem | Our Lady of Palestine | Small minority religion, Jewish state | |
| Italian Republic | Europe | Southern Europe | 47,000,000 | 80.0 | Italian | Rome | Saint Francis of Assisi, Saint Catherine of Siena | Majority religion | No |
| Jamaica | North America | Caribbean | 56,000 | 2.0 | English | Kingston | Our Lady of Perpetual Help | Minority religion | No |
| Japan | Asia | East Asia | 509,000 | 0.4 | Japanese | Tokyo | Saint Francis Xavier, Saint Peter Baptist | Minority religion | Yes |
| Jordan | Asia | Middle East | 50,000 | 0.5 | Arabic | Amman | Saint John the Baptist | Minority religion | Yes |
| Kazakhstan | Asia | Central Asia | 140,000 | 0.7 | Kazakh, Russian | Astana | Our Lady of Fatima | Minority religion, secular state | No |
| Kenya | Africa | East Africa | 13,200,000 | 24.0 | English, Swahili | Nairobi | Our Lady of Consolata | Minority religion | Yes |
| Kingdom of Italy | Europe | | 34,300,000 | 98.0 | Italian | Rome | Saint Francis of Assisi, Saint Catherine of Siena | Official religion | Yes |
| Kingdom of Naples | Europe | | 4,900,000 | 98.0 | Latin, Neapolitan, Italian | Naples | Saint Januarius, Saint Thomas Aquinas | Official religion | Yes |
| Kingdom of Sardinia | Europe | | 4,900,000 | 98.0 | Italian, Sardinian | Turin | Saint Maurice, Our Lady of Bonaria | Official religion | Yes |
| Kingdom of Sicily | Europe | | 1,960,000 | 98.0 | Latin, Sicilian, Italian | Palermo | Saint Rosalia, Saint Agatha | Official religion | Yes |
| Kingdom of the Two Sicilies | Europe | | 6,860,000 | 98.0 | Italian, Neapolitan, Sicilian | Naples | Saint Januarius, Saint Rosalia | Official religion | Yes |
| Kiribati | Australia | Central Pacific | 66,000 | 55.0 | Gilbertese, English | South Tarawa | Our Lady of the Rosary | Major religion, Protestantism also prominent | No |
| Kosovo | Europe | Southeastern Europe | 65,000 | 3.6 | Albanian, Serbian | Pristina | Saint Teresa of Calcutta | Minority religion, Muslim majority | No |
| Kuwait | Asia | Middle East | 350,000 | 8.0 | Arabic | Kuwait City | Our Lady of Arabia | Minority religion | No |
| Kyrgyzstan | Asia | Central Asia | 500 | 0.007 | Kyrgyz, Russian | Bishkek | None | Minority religion, Islam dominant | No |
| Laos | Asia | Southeast Asia | 100,000 | 1.3 | Lao | Vientiane | Our Lady of Lourdes | Minority religion, Buddhism dominant | No |
| Latvia | Europe | Northern Europe | 430,000 | 24.0 | Latvian | Riga | Our Lady of Aglona | Significant minority, Lutheran plurality | No |
| Latvia | Europe | Northern Europe | 430,000 | 24.0 | Latvian | Riga | Our Lady of Aglona | Significant minority, Lutheran plurality | No |
| Lebanon | Asia | Middle East | 1,900,000 | 36.0 | Arabic | Beirut | Our Lady of Lebanon, Saint Maron | Significant minority religion | Yes |
| Liberia | Africa | West Africa | 440,000 | 8.0 | English | Monrovia | Our Lady of Liberia | Minority religion | Yes |
| Liberia | Africa | West Africa | 440,000 | 8.0 | English | Monrovia | Our Lady of Liberia | Minority religion | Yes |
| Libya | Africa | North Africa | 2,000 | 0.03 | Arabic | Tripoli | Saint Victor the Moor | | |
| Liechtenstein | Europe | Central Europe | 30,000 | 75.0 | German | Vaduz | Saint Lucius | Official religion, constitutionally recognized | No |
| Luxembourg | Europe | Western Europe | 460,000 | 70.0 | Luxembourgish, French, German | Luxembourg City | Our Lady of Luxembourg, Saint Willibrord | Dominant religion, strong cultural role | No |
| Madagascar | Africa | Indian Ocean | 10,600,000 | 35.0 | Malagasy, French | Antananarivo | Our Lady of Madagascar | Minority religion | Yes |
| Malawi | Africa | Southeast Africa | 5,500,000 | 26.0 | English, Chichewa | Lilongwe | Our Lady of Malawi | Minority religion | Yes |
| Malaysia | Asia | Southeast Asia | 1,200,000 | 3.5 | Malay | Kuala Lumpur | Our Lady of Fatima | Minority religion, Islam dominant | No |
| Maldives | Asia | South Asia | 100 | 0.02 | Dhivehi | Malé | None | Clandestine minority religion | No |
| Mali | Africa | West Africa | 279,000 | 1.2 | French | Bamako | Our Lady of Mali | Minority religion | Yes |
| Malta | Europe | Southern Europe | 501,300 | 90.0 | Maltese, English | Valletta | Saint Paul, Saint Publius, Saint Agatha | Majority religion, constitutionally recognized | No |
| Marshall Islands | Australia | Central Pacific | 3,500 | 8.3 | Marshallese, English | Majuro | Our Lady of the Assumption | Minority religion, Protestantism dominant | No |
| Mauritania | Africa | Northwest Africa | 4,500 | 0.09 | Arabic | Nouakchott | Our Lady of Mauritania | Minority religion | Yes |
| Mauritius | Africa | Indian Ocean | 338,000 | 26.0 | English | Port Louis | Our Lady of Mauritius | Minority religion | Yes |
| Mexico | North America | Central America | 99,000,000 | 77.0 | Spanish | Mexico City | Our Lady of Guadalupe, Saint Juan Diego | Majority religion | No |
| Moldova | Europe | Eastern Europe | 20,000 | 0.8 | Romanian | Chișinău | Saint John the Baptist | Minority religion, Orthodoxy dominant | No |
| Monaco | Europe | Southern Europe | 32,760 | 84.0 | French | Monaco | Saint Devota | State religion, constitutionally recognized | No |
| Mongolia | Asia | East Asia | 1,500 | 0.04 | Mongolian | Ulaanbaatar | Our Lady of the Assumption | Small minority religion, Buddhist majority | No |
| Montenegro | Europe | Southeastern Europe | 21,000 | 3.4 | Montenegrin | Podgorica | Saint Peter of Cetinje | Minority religion, Orthodox majority | No |
| Morocco | Africa | North Africa | 23,000 | 0.06 | Arabic, Berber | Rabat | Our Lady of Morocco | Minority religion | Yes |
| Mozambique | Africa | Southeast Africa | 9,600,000 | 28.0 | Portuguese | Maputo | Our Lady of the Immaculate Conception | Minority religion | Yes |
| Myanmar | Asia | Southeast Asia | 700,000 | 1.29 | Burmese | Naypyidaw | Our Lady of Lourdes | Minority religion, Buddhism dominant | No |
| Namibia | Africa | Southern Africa | 440,000 | 16.9 | English | Windhoek | Our Lady of the Assumption | Significant minority religion, secular state | |
| Nauru | Australia | Central Pacific | 3,300 | 33.0 | Nauruan, English | Yaren | Our Lady of Perpetual Help | Minority religion, Protestantism dominant | No |
| Nepal | Asia | South Asia | 8,000 | 0.026 | Nepali | Kathmandu | Our Lady of the Assumption | Minority religion, Hinduism and Buddhism dominant | No |
| Netherlands | Europe | Western Europe | 3,600,000 | 20.0 | Dutch | Amsterdam | Saint Willibrord | Minority religion, secular state | |
| New Zealand | Australia | South Pacific | 470,000 | 9.0 | English, Māori, New Zealand Sign Language | Wellington | Our Lady of the Assumption | Minority religion, secularism and Protestantism prominent | No |
| Nicaragua | North America | Central America | 3,500,000 | 50.0 | Spanish | Managua | Our Lady of the Immaculate Conception, Saint James the Greater | Majority religion | No |
| Niger | Africa | West Africa | 20,000 | 0.07 | French | Niamey | Our Lady of Niger | Minority religion | Yes |
| North Korea | Asia | East Asia | 800 | 0.01 | Korean | Pyongyang | None | Clandestine minority religion | Yes |
| North Macedonia | Europe | Southeastern Europe | 15,000 | 0.7 | Macedonian | Skopje | Saint Clement of Ohrid | Minority religion, Orthodox and Muslim majority | No |
| Norway | Europe | Northern Europe | 165,000 | 3.0 | Norwegian, Sami | Oslo | Saint Olaf | Minority religion, Lutheran majority | No |
| Oman | Asia | Middle East | 50,000 | 1.1 | Arabic | Muscat | Our Lady of Arabia | Minority religion | No |
| Ottoman Empire | Asia, Europe, Africa | | 1,000,000 | 3.0 | Ottoman Turkish, Arabic | Constantinople | Saint John the Evangelist, Saint Polycarp | Minority religion, Islam dominant | Yes |
| Pakistan | Asia | South Asia | 1,200,000 | 0.48 | Urdu, English | Islamabad | Our Lady of Mariabad | Minority religion, Islam dominant | No |
| Palau | Australia | Western Pacific | 8,300 | 46.0 | Palauan, English | Ngerulmud | Our Lady of the Immaculate Conception | Significant minority religion, Protestantism and Modekngei also prominent | No |
| Panama | North America | Central America | 3,375,000 | 75.0 | Spanish | Panama City | Our Lady of Charity, Saint John Bosco | Majority religion | No |
| Papal States | Europe | | 2,940,000 | 98.0 | Latin, Italian | Rome | Saint Peter, Saint Paul | Official religion | Yes |
| Papua New Guinea | Australia | Melanesia | 2,700,000 | 26.0 | English, Tok Pisin, Hiri Motu | Port Moresby | Saint Michael the Archangel | Major religion, Christianity dominant | No |
| Paraguay | South America | Latin America | 6,500,000 | 89.0 | Spanish, Guarani | Asunción | Our Lady of the Assumption, Saint Roque González de Santa Cruz | Majority religion, constitutionally secular | No |
| Peru | South America | Latin America | 26,000,000 | 76.0 | Spanish, Quechua, Aymara | Lima | Saint Rose of Lima, Saint Martin de Porres | Majority religion, constitutionally secular | No |
| Philippines | Asia | Southeast Asia | 91,100,000 | 80.0 | Filipino, English | Quezon City | Our Lady of Peñafrancia, Santo Niño | Majority religion | Yes |
| Poland | Europe | Central Europe | 33,000,000 | 87.0 | Polish | Warsaw | Our Lady of Częstochowa, Saint John Paul II | Dominant religion, strong cultural influence | No |
| Portugal | Europe | Southern Europe | 8,505,000 | 81.0 | Portuguese | Lisbon | Our Lady of Fátima, Saint Anthony of Padua, Saint Vincent of Saragossa | Majority religion, constitutionally secular | No |
| Qatar | Asia | Middle East | 350,000 | 13.0 | Arabic | Doha | Our Lady of the Rosary | Minority religion | No |
| Republic of Armenia | Asia | South Caucasus | 15,000 | 0.5 | Armenian | Yerevan | None | Minority religion, Armenian Apostolic dominant (92%) | No |
| Republic of Azerbaijan | Asia | South Caucasus | 570 | 0.005 | Azerbaijani | Baku | None | Minority religion, Islam dominant (96%) | No |
| Republic of Slovenia | Europe | Central Europe | 1,470,000 | 70.0 | Slovene | Ljubljana | Saint Joseph, Saint Cyril | Majority religion | No |
| Republic of the Congo | Africa | Central Africa | 2,000,000 | 33.0 | French | Brazzaville | Our Lady of the Rosary | Largest religion, secular state | |
| Republic of Türkiye | Asia, Europe | Anatolia, Southeast Europe | 30,000 | 0.04 | Turkish | Ankara | Saint John the Evangelist, Saint Polycarp | Minority religion, Islam dominant (99%) | No |
| Roman Empire | Europe, Asia, Africa | | 10,000,000 | 14.0 | Latin, Greek | Rome | Saint Peter, Saint Paul | Official religion post-380 AD | Yes |
| Romania | Europe | Southeastern Europe | 1,100,000 | 6.0 | Romanian | Bucharest | Saint Anthony of Padua, Our Lady of Csíksomlyó | Minority religion, Orthodox majority | No |
| Russia | Europe, Asia | Eastern Europe, Northern Asia | 700,000 | 0.5 | Russian | Moscow | Saint Andrew, Saint Therese of Lisieux | Minority religion, Orthodox majority | No |
| Rwanda | Africa | East Africa | 6,300,000 | 45.0 | Kinyarwanda, English, French, Swahili | Kigali | Our Lady of Rwanda | Minority religion | Yes |
| Saint Kitts and Nevis | North America | Caribbean | 5,400 | 10.0 | English | Basseterre | Saint Christopher | Minority religion | No |
| Saint Lucia | North America | Caribbean | 112,000 | 61.0 | English | Castries | Saint Lucy | Majority religion | No |
| Saint Vincent and the Grenadines | North America | Caribbean | 7,300 | 7.0 | English | Kingstown | Saint Vincent Ferrer | Minority religion | No |
| Samoa | Australia | South Pacific | 40,000 | 19.5 | Samoan, English | Apia | Our Lady of the Rosary | Minority religion, Congregationalism and Methodism dominant | No |
| San Marino | Europe | Southern Europe | 31,280 | 92.0 | Italian | San Marino | Saint Marinus, Saint Agatha | Majority religion, constitutionally recognized | No |
| São Tomé and Príncipe | Africa | Gulf of Guinea | 160,000 | 70.0 | Portuguese | São Tomé | Our Lady of São Tomé | Majority religion | Yes |
| Saudi Arabia | Asia | Middle East | 1,500,000 | 4.0 | Arabic | Riyadh | None | Covert minority religion | No |
| Scotland | Europe | Northern Europe | 700,000 | 12.7 | English, Scottish Gaelic, Scots | Edinburgh | Saint Andrew, Saint Margaret of Scotland, Saint Columba | Minority religion; largest after Church of Scotland | No |
| Senegal | Africa | West Africa | 920,000 | 5.0 | French | Dakar | Our Lady of Senegal | Minority religion | Yes |
| Serbia | Europe | Southeastern Europe | 290,000 | 4.4 | Serbian | Belgrade | Saint John of Nepomuk | Minority religion, Orthodox majority | No |
| Seychelles | Africa | Indian Ocean | 76,000 | 76.0 | English, French, Seychellois Creole | Victoria | Our Lady of Seychelles | Majority religion | Yes |
| Sierra Leone | Africa | West Africa | 1,200,000 | 13.0 | English | Freetown | Our Lady of Sierra Leone | Minority religion | Yes |
| Singapore | Asia | Southeast Asia | 200,000 | 3.4 | English, Malay, Mandarin, Tamil | Singapore | Our Lady Star of the Sea | Minority religion, multi-religious society | No |
| Slovak Republic | Europe | Central Europe | 3,380,000 | 62.0 | Slovak | Bratislava | Our Lady of Sorrows, Saint Cyril | Majority religion | No |
| Socialist Federal Republic of Yugoslavia | Europe | | 6,900,000 | 30.0 | Serbo-Croatian, Slovene, Macedonian | Belgrade | Saint Joseph, Saint Leopold Mandić | Minority religion, atheism state policy | Yes |
| Solomon Islands | Australia | South Pacific | 140,000 | 19.0 | English | Honiara | Our Lady of Guadalcanal | Minority religion, Anglicanism and Pentecostalism dominant | No |
| Somalia | Africa | Horn of Africa | 100 | 0.0006 | Somali, Arabic | Mogadishu | Our Lady of Somalia | Minority religion | Yes |
| South Africa | Africa | Southern Africa | 3,700,000 | 6.0 | English, Afrikaans, Zulu, Xhosa, others | Pretoria | Our Lady of South Africa | Minority religion | Yes |
| South Korea | Asia | East Asia | 5,900,000 | 11.3 | Korean | Seoul | Our Lady of the Immaculate Conception | Significant minority religion | Yes |
| South Sudan | Africa | East Africa | 5,100,000 | 44.0 | English | Juba | Our Lady of South Sudan | Minority religion | Yes |
| Spain | Europe | Southern Europe | 28,700,000 | 60.0 | Spanish | Madrid | Our Lady of the Pillar, Saint James the Great, Saint Teresa of Ávila | Majority religion, constitutionally secular | No |
| Sri Lanka | Asia | South Asia | 1,400,000 | 6.2 | Sinhala, Tamil | Sri Jayawardenepura Kotte | Our Lady of Madhu | Minority religion | Yes |
| Sudan | Africa | Northeast Africa | 490,000 | 1.0 | Arabic, English | Khartoum | Saint Josephine Bakhita | Small minority religion, Islamic state | |
| Suriname | South America | Caribbean | 135,000 | 21.0 | Dutch | Paramaribo | Saint Peter Claver | Significant minority religion, Christianity dominant | No |
| Sweden | Europe | Northern Europe | 125,000 | 1.2 | Swedish | Stockholm | Saint Bridget of Sweden | Minority religion, secular majority | No |
| Switzerland | Europe | Central Europe | 3,300,000 | 37.0 | German, French, Italian, Romansh | Bern | Saint Nicholas of Flüe, Our Lady of Einsiedeln | Major religion, alongside Protestantism | No |
| Syria | Asia | Middle East | 400,000 | 1.7 | Arabic | Damascus | Saint Paul the Apostle | Small minority religion, secular state | |
| Taiwan | Asia | East Asia | 300,000 | 1.3 | Mandarin Chinese | Taipei | Our Lady of China | Minority religion | Yes |
| Tajikistan | Asia | Central Asia | 150 | 0.0015 | Tajik | Dushanbe | None | Minority religion, Islam dominant | No |
| Tanzania | Africa | East Africa | 21,600,000 | 32.0 | Swahili, English | Dodoma | Our Lady of Tanzania | Minority religion | Yes |
| Thailand | Asia | Southeast Asia | 388,468 | 0.58 | Thai | Bangkok | Our Lady of Lourdes | Minority religion, Buddhism dominant | No |
| The Gambia | Africa | West Africa | 84,000 | 3.0 | English | Banjul | Our Lady of Peace | Minority religion | Yes |
| Timor-Leste | Asia | Southeast Asia | 1,260,000 | 97.0 | Tetum, Portuguese | Dili | Our Lady of Aitara | Dominant religion, constitutionally secular | No |
| Togo | Africa | West Africa | 2,500,000 | 28.0 | French | Lomé | Our Lady of Togo | Minority religion | Yes |
| Tonga | Australia | South Pacific | 16,000 | 15.0 | Tongan, English | Nukuʻalofa | Our Lady of Perpetual Help | Minority religion, Methodism and Mormonism dominant | No |
| Trinidad and Tobago | North America | Caribbean | 300,000 | 20.0 | English | Port of Spain | Our Lady of Fatima | Significant minority religion | No |
| Tunisia | Africa | North Africa | 25,000 | 0.2 | Arabic | Tunis | Saint Cyprian of Carthage | | |
| Turkmenistan | Asia | Central Asia | 1,000 | 0.01 | Turkmen | Ashgabat | Saint Joseph | Small minority religion, Islamic majority | No |
| Tuvalu | Australia | South Pacific | 100 | 0.8 | Tuvaluan, English | Funafuti | Our Lady of the Rosary | Minority religion, Protestantism dominant | No |
| Uganda | Africa | East Africa | 19,700,000 | 40.0 | English, Swahili | Kampala | Our Lady of Uganda | Minority religion | Yes |
| Ukraine | Europe | Eastern Europe | 4,500,000 | 11.0 | Ukrainian | Kyiv | Our Lady of Zarvanytsia | Significant minority, Orthodox majority | No |
| Union of Soviet Socialist Republics | Europe, Asia | | 10,000,000 | 3.5 | Russian | Moscow | Saint Vladimir, Saint Olga | Minority religion, atheism state policy | Yes |
| United Arab Emirates | Asia | Middle East | 950,000 | 10.0 | Arabic | Abu Dhabi | Our Lady of Arabia | Minority religion | No |
| United Kingdom | Europe | Northern Europe | 5,500,000 | 8.0 | English | London | Saint George, Saint Andrew, Saint David, Saint Patrick | Minority religion, Anglicanism prominent | No |
| United States of America | North America | North America | 69,000,000 | 20.0 | None (English de facto) | Washington, D.C. | Our Lady of the Immaculate Conception | Minority religion | No |
| Uruguay | South America | Latin America | 1,400,000 | 40.0 | Spanish | Montevideo | Our Lady of the Thirty-Three, Saint Philip and Saint James | Plurality religion, constitutionally secular | No |
| Uzbekistan | Asia | Central Asia | 3,000 | 0.008 | Uzbek | Tashkent | None | Minority religion, Islam dominant | No |
| Vanuatu | Australia | South Pacific | 40,000 | 12.0 | Bislama, English, French | Port Vila | Our Lady of Lourdes | Minority religion, Protestantism and indigenous beliefs dominant | No |
| Venezuela | South America | Northern South America | 20,300,000 | 70.0 | Spanish | Caracas | Our Lady of Coromoto | Majority religion | No |
| Vietnam | Asia | Southeast Asia | 7,000,000 | 6.8 | Vietnamese | Hanoi | Our Lady of La Vang | Minority religion, Buddhism and secularism dominant | No |
| West Francia | Europe | | 2,700,000 | 90.0 | Latin, Old French | Paris | Saint Martin of Tours, Saint Denis | State religion under Carolingian and Capetian rulers | |
| Yemen | Asia | Middle East | 1,000 | 0.01 | Arabic | Sana’a | None | Negligible minority religion | No |
| Zambia | Africa | Southern Africa | 4,200,000 | 20.0 | English | Lusaka | Our Lady of Africa | Significant minority religion, secular state | |
| Zimbabwe | Africa | Southern Africa | 2,200,000 | 13.0 | English, Shona, Ndebele | Harare | Our Lady of Zimbabwe | Minority religion | Yes |